485BPOS

As filed with the Securities and Exchange Commission on February 17, 2016

Securities Act Registration No. 33-10451

Investment Company Act Registration No. 811-4920

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933                            X

Post-Effective Amendment No. 91                X

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940   X

Amendment No. 93                                         X

(Check appropriate box or boxes)

WASATCH FUNDS TRUST

(Exact Name of Registrant as Specified in Charter)

505 Wakara Way, 3rd Floor

Salt Lake City, UT 84108

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: (801) 533-0777

(Name and Address of Agent for Service)	Copy to:
Samuel S. Stewart, Jr. Wasatch Advisors, Inc. 505 Wakara Way, 3rd Floor Salt Lake City, UT 84108	Eric F. Fess Chapman and Cutler LLP 111 West Monroe Street Chicago, IL 60603

Approximate Date of Proposed Public Offering: As soon as practicable following effectiveness.

It is proposed that this filing will become effective:

(X) immediately upon filing pursuant to paragraph (b)

(   ) on                      pursuant to paragraph (b)

(   ) 60 days after filing pursuant to paragraph (a)(1)

(   ) on                      pursuant to paragraph (a)(1)

(   ) 75 days after filing pursuant to paragraph (a)(2)

(   ) on                      pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

(   ) this Post-Effective Amendment designates a new effective date for a previously filed Post-Effective Amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended and the Investment Company Act of 1940, as amended, the Registrant certifies that this Post-Effective Amendment No. 91 to the Registration Statement meets all the requirements for effectiveness pursuant to Rule 485(b) of the Securities Act of 1933, as amended, and the Registrant has duly caused this Post-Effective Amendment No. 91 under the Securities Act of 1933, as amended and Post-Effective Amendment No. 93 under the Investment Company Act of 1940, as amended to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Salt Lake City, and the State of Utah on the 17th day of February, 2016.

WASATCH FUNDS TRUST
By	/s/ Samuel S. Stewart
	Samuel S. Stewart, Jr., Ph.D.,
	President

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the date indicated.

Signature	Title	Date
/s/ Samuel S. Stewart Samuel S. Stewart, Jr., Ph.D.	President and Trustee (principal  executive officer)	February 17, 2016
/s/ Cindy B. Firestone Cindy B. Firestone	Treasurer (principal financial and  accounting officer)	February 17, 2016
James U. Jensen* James U. Jensen, Esquire	Trustee	February 17, 2016
D. James Croft* D. James Croft	Trustee	February 17, 2016
Miriam M. Allison* Miriam M. Allison	Trustee	February 17, 2016
Heikki Rinne* Heikki Rinne	Trustee	February 17, 2016
Kristen M. Fletcher* Kristen M. Fletcher	Trustee	February 17, 2016
/s/ Russell L. Biles
Russell L. Biles
Attorney-in-Fact
February 17, 2016

*Signed pursuant to powers of attorney are incorporated herein by reference to Exhibit (q) in Post-Effective Amendment No. 50 to the Registrant’s Registration Statement on Form N-1A filed with the Commission on March 31, 2010, a power of attorney incorporated herein by reference to Exhibit q-1 in Post-Effective Amendment No. 65 to the Registrant’s Registration Statement on Form N-1A filed with the Commission on October 2, 2012 and a power of attorney incorporated herein by reference to Exhibit q-2 in Post-Effective Amendment No. 87 to the Registrant’s Registration Statement on Form N-1A filed with the Commission on January 28, 2015.

1

Exhibit Index
Exhibit No.
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

2

XML

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Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Sep. 30, 2015
Registrant Name	dei_EntityRegistrantName	WASATCH FUNDS TRUST
Central Index Key	dei_EntityCentralIndexKey	0000806633
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Jan. 28, 2016
Document Effective Date	dei_DocumentEffectiveDate	Jan. 31, 2016
Prospectus Date	rr_ProspectusDate	Jan. 31, 2016

XML

Investor Class | Wasatch Core Growth Fund

WASATCH CORE GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Core Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Core Growth Fund Investor Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.17%
Total Annual Fund Operating Expenses	1.17%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Core Growth Fund | Investor Class | USD ($)	119	372	644	1,420

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The companies in which we invest are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We focus on companies that we consider to be high quality. We use a process of “bottom-up” fundamental analysis to look for individual companies that we believe are stable and have the potential to grow steadily for long periods of time. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH CORE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	29.50%
Worst — 12/31/2008	-27.03%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Core Growth Fund	1 Year	5 Years	10 Years
Investor Class	3.92%	12.45%	7.50%
Investor Class | Return After Taxes on Distributions	1.17%	11.64%	6.60%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	4.54%	9.96%	6.02%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	(4.41%)	9.19%	6.80%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	(1.38%)	10.67%	7.95%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Core Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH CORE GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The companies in which we invest are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We focus on companies that we consider to be high quality. We use a process of “bottom-up” fundamental analysis to look for individual companies that we believe are stable and have the potential to grow steadily for long periods of time. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH CORE GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	29.50%
Worst — 12/31/2008	-27.03%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Core Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.17%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.17%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 119

3 Years

rr_ExpenseExampleYear03

372

5 Years

rr_ExpenseExampleYear05

644

10 Years

rr_ExpenseExampleYear10

$ 1,420

2006

rr_AnnualReturn2006

6.68%

2007

rr_AnnualReturn2007

6.40%

2008

rr_AnnualReturn2008

(44.34%)

2009

rr_AnnualReturn2009

45.16%

2010

rr_AnnualReturn2010

24.99%

2011

rr_AnnualReturn2011

5.09%

2012

rr_AnnualReturn2012

19.19%

2013

rr_AnnualReturn2013

30.18%

2014

rr_AnnualReturn2014

6.10%

2015

rr_AnnualReturn2015

3.92%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

29.50%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.03%)

1 Year

rr_AverageAnnualReturnYear01

3.92%

5 Years

rr_AverageAnnualReturnYear05

12.45%

10 Years

rr_AverageAnnualReturnYear10

7.50%

Investor Class | Wasatch Core Growth Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.17%

5 Years

rr_AverageAnnualReturnYear05

11.64%

10 Years

rr_AverageAnnualReturnYear10

6.60%

Investor Class | Wasatch Core Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.54%

5 Years

rr_AverageAnnualReturnYear05

9.96%

10 Years

rr_AverageAnnualReturnYear10

6.02%

Investor Class | Wasatch Core Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.41%)

5 Years

rr_AverageAnnualReturnYear05

9.19%

10 Years

rr_AverageAnnualReturnYear10

6.80%

Investor Class | Wasatch Core Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.38%)

5 Years

rr_AverageAnnualReturnYear05

10.67%

10 Years

rr_AverageAnnualReturnYear10

7.95%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Investor Class | Wasatch Emerging India Fund

WASATCH EMERGING INDIA FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Emerging India Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Emerging India Fund Investor Class Shares
Management Fee	1.25%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.62%
Total Annual Fund Operating Expenses	1.87%
Expense Reimbursement	(0.12%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.75%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Emerging India Fund | Investor Class | USD ($)	178	576	1,000	2,181

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 36% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies tied economically to India.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies tied economically to India. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
We will generally consider qualifying investments to be in companies that are listed on an Indian exchange, that have at least 50% of their assets in India, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in India.
The Fund is expected to invest across market capitalization levels, ranging from small capitalization stocks to larger capitalization stocks. However, we expect the Fund to invest a significant portion of its assets in small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We use a process of quantitative screening followed by “bottom up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.
We may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Indian Market Risk. Government actions, bureaucratic obstacles and inconsistent economic and tax reform within the Indian government have had a significant effect on the economy and could adversely affect market conditions, deter economic growth and reduce the profitability of private enterprises. Global factors and foreign actions may inhibit the flow of foreign capital on which India is dependent to sustain its growth. Large portions of many Indian companies remain in the hands of their founders (including members of their families). Family-controlled companies may have weaker and less transparent corporate governance, which increases the potential for loss and unequal treatment of investors. India experiences many of the market risks associated with developing economies, including relatively low levels of liquidity, which may result in extreme volatility in the prices of Indian securities. Religious, cultural and military disputes persist in India, and between India and Pakistan (as well as sectarian groups within each country). The threat of aggression in the region could hinder development of the Indian economy, and escalating tensions could impact the broader region, including China.
Because the Fund concentrates its investments in a single region of the world, the value of the Fund’s shares may be affected by events that adversely affect India and may fluctuate more than the value of a less concentrated fund’s shares.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING INDIA FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2012	21.43%
Worst — 6/30/2012	-6.95%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Emerging India Fund		1 Year	Since Inception	Inception Date
Investor Class		4.16%	9.83%	Apr. 26, 2011
Investor Class | Return After Taxes on Distributions		3.81%	9.71%	Apr. 26, 2011
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		2.63%	7.77%	Apr. 26, 2011
MSCI India Investable Market Index (reflects no deductions for fees, expenses or taxes)	[1]	(4.69%)	(1.23%)	Apr. 26, 2011

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Emerging India Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING INDIA FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 36% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

36.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in companies tied economically to India.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies tied economically to India. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
We will generally consider qualifying investments to be in companies that are listed on an Indian exchange, that have at least 50% of their assets in India, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in India.
The Fund is expected to invest across market capitalization levels, ranging from small capitalization stocks to larger capitalization stocks. However, we expect the Fund to invest a significant portion of its assets in small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We use a process of quantitative screening followed by “bottom up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.
We may also invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Indian Market Risk. Government actions, bureaucratic obstacles and inconsistent economic and tax reform within the Indian government have had a significant effect on the economy and could adversely affect market conditions, deter economic growth and reduce the profitability of private enterprises. Global factors and foreign actions may inhibit the flow of foreign capital on which India is dependent to sustain its growth. Large portions of many Indian companies remain in the hands of their founders (including members of their families). Family-controlled companies may have weaker and less transparent corporate governance, which increases the potential for loss and unequal treatment of investors. India experiences many of the market risks associated with developing economies, including relatively low levels of liquidity, which may result in extreme volatility in the prices of Indian securities. Religious, cultural and military disputes persist in India, and between India and Pakistan (as well as sectarian groups within each country). The threat of aggression in the region could hinder development of the Indian economy, and escalating tensions could impact the broader region, including China.
Because the Fund concentrates its investments in a single region of the world, the value of the Fund’s shares may be affected by events that adversely affect India and may fluctuate more than the value of a less concentrated fund’s shares.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH EMERGING INDIA FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/2012	21.43%
Worst — 6/30/2012	-6.95%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Investor Class | Wasatch Emerging India Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.62%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.87%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.12%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.75%

1 Year

rr_ExpenseExampleYear01

$ 178

3 Years

rr_ExpenseExampleYear03

576

5 Years

rr_ExpenseExampleYear05

1,000

10 Years

rr_ExpenseExampleYear10

$ 2,181

2012

rr_AnnualReturn2012

33.77%

2013

rr_AnnualReturn2013

(1.46%)

2014

rr_AnnualReturn2014

45.40%

2015

rr_AnnualReturn2015

4.16%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2012

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

21.43%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2012

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(6.95%)

1 Year

rr_AverageAnnualReturnYear01

4.16%

Since Inception

rr_AverageAnnualReturnSinceInception

9.83%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Investor Class | Wasatch Emerging India Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.81%

Since Inception

rr_AverageAnnualReturnSinceInception

9.71%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Investor Class | Wasatch Emerging India Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.63%

Since Inception

rr_AverageAnnualReturnSinceInception

7.77%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Investor Class | Wasatch Emerging India Fund | MSCI India Investable Market Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.69%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

(1.23%)

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

^[3]

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Investor Class | Wasatch Emerging Markets Select Fund

WASATCH EMERGING MARKETS SELECT FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Emerging Markets Select Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Emerging Markets Select Fund Investor Class Shares
Management Fee	1.00%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.74%
Interest Expense	0.01%
Total Annual Fund Operating Expenses	1.75%
Expense Reimbursement	(0.24%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.51%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Emerging Markets Select Fund | Investor Class | USD ($)	153	527	926	2,042

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, materials, telecommunication services, and in convertible securities.
The Fund may invest in initial public offerings (IPOs) and early stage companies.
Under normal market conditions, the Fund will generally invest in 30 to 50 companies. However, we may invest in fewer or more companies when we believe that doing so will help our efforts to achieve the Fund’s investment objective.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Convertible Securities Risk. The Fund may invest in convertible securities, which are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and have less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security then the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING MARKETS SELECT FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2014	4.37%
Worst — 9/30/2015	-15.14%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Emerging Markets Select Fund		1 Year	Since Inception	Inception Date
Investor Class		(17.16%)	(5.24%)	Dec. 13, 2012
Investor Class | Return After Taxes on Distributions		(17.16%)	(5.20%)	Dec. 13, 2012
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		(9.71%)	(3.86%)	Dec. 13, 2012
MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(14.92%)	(6.22%)	Dec. 13, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Effective January 31, 2016, the management fee was reduced from 1.25% to 1.00%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Emerging Markets Select Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING MARKETS SELECT FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

46.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, materials, telecommunication services, and in convertible securities.
The Fund may invest in initial public offerings (IPOs) and early stage companies.
Under normal market conditions, the Fund will generally invest in 30 to 50 companies. However, we may invest in fewer or more companies when we believe that doing so will help our efforts to achieve the Fund’s investment objective.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, materials, telecommunication services, and in convertible securities.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Convertible Securities Risk. The Fund may invest in convertible securities, which are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and have less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security then the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund's performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, of the Fund's Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH EMERGING MARKETS SELECT FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2014	4.37%
Worst — 9/30/2015	-15.14%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund's returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Emerging Markets Select Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Interest Expense

rr_Component2OtherExpensesOverAssets

0.01%

Other Expenses

rr_OtherExpensesOverAssets

0.74%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.75%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.24%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.51%

1 Year

rr_ExpenseExampleYear01

$ 153

3 Years

rr_ExpenseExampleYear03

527

5 Years

rr_ExpenseExampleYear05

926

10 Years

rr_ExpenseExampleYear10

$ 2,042

2013

rr_AnnualReturn2013

(3.27%)

2014

rr_AnnualReturn2014

4.01%

2015

rr_AnnualReturn2015

(17.16%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2014

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.37%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.14%)

1 Year

rr_AverageAnnualReturnYear01

(17.16%)

Since Inception

rr_AverageAnnualReturnSinceInception

(5.24%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Investor Class | Wasatch Emerging Markets Select Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(17.16%)

Since Inception

rr_AverageAnnualReturnSinceInception

(5.20%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Investor Class | Wasatch Emerging Markets Select Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(9.71%)

Since Inception

rr_AverageAnnualReturnSinceInception

(3.86%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Investor Class | Wasatch Emerging Markets Select Fund | MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.92%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

(6.22%)

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

^[3]

[1] Effective January 31, 2016, the management fee was reduced from 1.25% to 1.00%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Investor Class | Wasatch Emerging Markets Small Cap Fund

WASATCH EMERGING MARKETS SMALL CAP FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Emerging Markets Small Cap Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Emerging Markets Small Cap Fund Investor Class Shares
Management Fee	1.65%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.26%
Total Annual Fund Operating Expenses	1.91%	[2]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Emerging Markets Small Cap Fund | Investor Class | USD ($)	194	600	1,032	2,233

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 59% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small companies tied economically to emerging markets.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of US$3 billion or the market capitalization of the largest company in the Morgan Stanley Capital International (MSCI) Emerging Markets Small Cap Index during the most recent 12-month period. As of its most recent reconstitution date, the market capitalization of the largest company in the MSCI Emerging Markets Small Cap Index was $6.4 billion. The capitalization of the largest company in the MSCI Emerging Markets Small Cap Index is subject to change at its next reconstitution date.
Emerging market countries are those currently included in the MSCI Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING MARKETS SMALL CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	56.10%
Worst — 12/31/2008	-32.16%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Emerging Markets Small Cap Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Class		(9.35%)	(0.64%)	2.79%	Oct. 01, 2007
Investor Class | Return After Taxes on Distributions		(9.35%)	(0.71%)	2.71%	Oct. 01, 2007
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		(5.29%)	(0.41%)	2.21%	Oct. 01, 2007
MSCI Emerging Markets Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	(6.85%)	(3.29%)	(0.64%)	Oct. 01, 2007
MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(14.92%)	(4.81%)	(2.63%)	Oct. 01, 2007

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Effective January 31, 2016, the management fee was reduced from 1.75% to 1.65%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Emerging Markets Small Cap Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING MARKETS SMALL CAP FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 59% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

59.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small companies tied economically to emerging markets.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of US$3 billion or the market capitalization of the largest company in the Morgan Stanley Capital International (MSCI) Emerging Markets Small Cap Index during the most recent 12-month period. As of its most recent reconstitution date, the market capitalization of the largest company in the MSCI Emerging Markets Small Cap Index was $6.4 billion. The capitalization of the largest company in the MSCI Emerging Markets Small Cap Index is subject to change at its next reconstitution date.
Emerging market countries are those currently included in the MSCI Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund's performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund's Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH EMERGING MARKETS SMALL CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	56.10%
Worst — 12/31/2008	-32.16%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund's returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Emerging Markets Small Cap Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.65%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.26%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.91%

^[2]

1 Year

rr_ExpenseExampleYear01

$ 194

3 Years

rr_ExpenseExampleYear03

600

5 Years

rr_ExpenseExampleYear05

1,032

10 Years

rr_ExpenseExampleYear10

$ 2,233

2008

rr_AnnualReturn2008

(57.08%)

2009

rr_AnnualReturn2009

117.72%

2010

rr_AnnualReturn2010

41.22%

2011

rr_AnnualReturn2011

(14.01%)

2012

rr_AnnualReturn2012

27.75%

2013

rr_AnnualReturn2013

(3.60%)

2014

rr_AnnualReturn2014

0.89%

2015

rr_AnnualReturn2015

(9.35%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

56.10%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(32.16%)

1 Year

rr_AverageAnnualReturnYear01

(9.35%)

5 Years

rr_AverageAnnualReturnYear05

(0.64%)

Since Inception

rr_AverageAnnualReturnSinceInception

2.79%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Investor Class | Wasatch Emerging Markets Small Cap Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(9.35%)

5 Years

rr_AverageAnnualReturnYear05

(0.71%)

Since Inception

rr_AverageAnnualReturnSinceInception

2.71%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Investor Class | Wasatch Emerging Markets Small Cap Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.29%)

5 Years

rr_AverageAnnualReturnYear05

(0.41%)

Since Inception

rr_AverageAnnualReturnSinceInception

2.21%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Investor Class | Wasatch Emerging Markets Small Cap Fund | MSCI Emerging Markets Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(6.85%)

^[3]

5 Years

rr_AverageAnnualReturnYear05

(3.29%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

(0.64%)

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

^[3]

Investor Class | Wasatch Emerging Markets Small Cap Fund | MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.92%)

^[3]

5 Years

rr_AverageAnnualReturnYear05

(4.81%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

(2.63%)

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

^[3]

[1] Effective January 31, 2016, the management fee was reduced from 1.75% to 1.65%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Investor Class | Wasatch Frontier Emerging Small Countries Fund

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Frontier Emerging Small Countries Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Frontier Emerging Small Countries Fund Investor Class Shares
Management Fee	1.75%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.53%
Total Annual Fund Operating Expenses	2.28%
Expense Reimbursement	(0.03%)	[1]
Total Annual Fund Operating Expenses After Expense Reimbursement	2.25%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Frontier Emerging Small Countries Fund | Investor Class | USD ($)	228	709	1,217	2,613

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 34% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in the equity securities of companies of all market capitalizations that are tied economically to frontier markets and small emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to frontier markets and small emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
“Frontier markets” include any country that is outside the Morgan Stanley Capital International (MSCI) All Country World Index, and also any country that is currently included in the Russell Frontier Index, the S&P Frontier Broad Market Index (BMI), the MSCI Frontier Markets Index, or similar market indices, or any country that, in our opinion, has similar characteristics regardless of its inclusion in an index.
“Emerging markets” include those countries currently considered to be developing as per their inclusion in the MSCI Emerging Markets Index. We consider a “small emerging market country” to be any country that individually constitutes not more than 7% of the MSCI Emerging Markets Index or the S&P Emerging BMI.
We will generally consider qualifying investments to be in companies that are listed on an exchange in a frontier market or small emerging market country, that are legally domiciled in a frontier market or small emerging market country, that have at least 50% of their assets in a frontier market or small emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services provided in a frontier market or small emerging market country. The Fund will not be required to sell a security because the market to which it is economically tied is no longer what we consider to be a frontier market or a small emerging market country.
In general, frontier markets and small emerging market countries, with the exception of the oil-producing Persian Gulf States, tend to have relatively low gross national product per capita compared to the larger traditionally-recognized emerging markets and the world’s major developed economies. Frontier and small emerging market countries include the least developed markets even by emerging market standards. We believe frontier markets and small emerging market countries offer investment opportunities that arise from long-term trends in demographics, deregulation, offshore outsourcing and improving corporate governance.
The Fund may invest in the equity securities of companies of any size, although we expect a significant portion of the Fund’s assets to be invested in companies with market capitalizations of under US$3 billion at the time of purchase.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to frontier markets and small emerging market countries.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, materials and telecommunication services.
We may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries, and in particular small emerging market countries, include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Frontier Markets Risk. In addition to the risks of investing in foreign securities and emerging markets, frontier market securities involve unique risks, such as exposure to economies less diverse and mature than those of the U.S. or more established foreign markets. Economic or political instability may cause larger price changes in frontier market securities than in securities of issuers based in more developed foreign countries, including securities of issuers in larger emerging markets. Frontier markets generally receive less investor attention than developed markets or larger emerging markets. These risks can result in the potential for extreme price volatility and illiquidity.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Liquidity Risk. The trading market for a particular security or type of security in which the Fund invests may be significantly less liquid than domestic or even emerging markets, and there may be little or no trading volume for a period of time for a particular security. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities quickly at the currently marked price when necessary to meet the Fund’s liquidity needs or in response to a specific economic event. It may be difficult at times to sell such securities at any price, which could impact not only the daily Fund NAV, but also the composition of the portfolio if other securities must be sold to meet the Fund’s liquidity needs. Additionally, market quotations for such securities may be volatile affecting the daily NAV of the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2013	8.33%
Worst — 9/30/2015	-7.05%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Frontier Emerging Small Countries Fund		1 Year	Since Inception	Inception Date
Investor Class		(12.10%)	8.84%	Jan. 31, 2012
Investor Class | Return After Taxes on Distributions		(11.92%)	8.84%	Jan. 31, 2012
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		(6.60%)	7.11%	Jan. 31, 2012
MSCI Frontier Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(18.30%)	1.35%	Jan. 31, 2012
MSCI Frontier Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(14.46%)	5.87%	Jan. 31, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Frontier Emerging Small Countries Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 34% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

34.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in the equity securities of companies of all market capitalizations that are tied economically to frontier markets and small emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to frontier markets and small emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
“Frontier markets” include any country that is outside the Morgan Stanley Capital International (MSCI) All Country World Index, and also any country that is currently included in the Russell Frontier Index, the S&P Frontier Broad Market Index (BMI), the MSCI Frontier Markets Index, or similar market indices, or any country that, in our opinion, has similar characteristics regardless of its inclusion in an index.
“Emerging markets” include those countries currently considered to be developing as per their inclusion in the MSCI Emerging Markets Index. We consider a “small emerging market country” to be any country that individually constitutes not more than 7% of the MSCI Emerging Markets Index or the S&P Emerging BMI.
We will generally consider qualifying investments to be in companies that are listed on an exchange in a frontier market or small emerging market country, that are legally domiciled in a frontier market or small emerging market country, that have at least 50% of their assets in a frontier market or small emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services provided in a frontier market or small emerging market country. The Fund will not be required to sell a security because the market to which it is economically tied is no longer what we consider to be a frontier market or a small emerging market country.
In general, frontier markets and small emerging market countries, with the exception of the oil-producing Persian Gulf States, tend to have relatively low gross national product per capita compared to the larger traditionally-recognized emerging markets and the world’s major developed economies. Frontier and small emerging market countries include the least developed markets even by emerging market standards. We believe frontier markets and small emerging market countries offer investment opportunities that arise from long-term trends in demographics, deregulation, offshore outsourcing and improving corporate governance.
The Fund may invest in the equity securities of companies of any size, although we expect a significant portion of the Fund’s assets to be invested in companies with market capitalizations of under US$3 billion at the time of purchase.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to frontier markets and small emerging market countries.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, materials and telecommunication services.
We may also invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, materials and telecommunication services.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries, and in particular small emerging market countries, include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Frontier Markets Risk. In addition to the risks of investing in foreign securities and emerging markets, frontier market securities involve unique risks, such as exposure to economies less diverse and mature than those of the U.S. or more established foreign markets. Economic or political instability may cause larger price changes in frontier market securities than in securities of issuers based in more developed foreign countries, including securities of issuers in larger emerging markets. Frontier markets generally receive less investor attention than developed markets or larger emerging markets. These risks can result in the potential for extreme price volatility and illiquidity.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Liquidity Risk. The trading market for a particular security or type of security in which the Fund invests may be significantly less liquid than domestic or even emerging markets, and there may be little or no trading volume for a period of time for a particular security. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities quickly at the currently marked price when necessary to meet the Fund’s liquidity needs or in response to a specific economic event. It may be difficult at times to sell such securities at any price, which could impact not only the daily Fund NAV, but also the composition of the portfolio if other securities must be sold to meet the Fund’s liquidity needs. Additionally, market quotations for such securities may be volatile affecting the daily NAV of the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund's performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, of the Fund's Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/2013	8.33%
Worst — 9/30/2015	-7.05%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund's returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Frontier Emerging Small Countries Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.75%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.53%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.28%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.03%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

2.25%

1 Year

rr_ExpenseExampleYear01

$ 228

3 Years

rr_ExpenseExampleYear03

709

5 Years

rr_ExpenseExampleYear05

1,217

10 Years

rr_ExpenseExampleYear10

$ 2,613

2013

rr_AnnualReturn2013

18.00%

2014

rr_AnnualReturn2014

1.69%

2015

rr_AnnualReturn2015

(12.10%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2013

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

8.33%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(7.05%)

1 Year

rr_AverageAnnualReturnYear01

(12.10%)

Since Inception

rr_AverageAnnualReturnSinceInception

8.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Investor Class | Wasatch Frontier Emerging Small Countries Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(11.92%)

Since Inception

rr_AverageAnnualReturnSinceInception

8.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Investor Class | Wasatch Frontier Emerging Small Countries Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(6.60%)

Since Inception

rr_AverageAnnualReturnSinceInception

7.11%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Investor Class | Wasatch Frontier Emerging Small Countries Fund | MSCI Frontier Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(18.30%)

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

1.35%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

^[2]

Investor Class | Wasatch Frontier Emerging Small Countries Fund | MSCI Frontier Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.46%)

^[2]

Since Inception

rr_AverageAnnualReturnSinceInception

5.87%

^[2]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

^[2]

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Investor Class | Wasatch Global Opportunities Fund

WASATCH GLOBAL OPPORTUNITIES FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Global Opportunities Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Global Opportunities Fund Investor Class Shares
Management Fee	1.25%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.31%
Total Annual Fund Operating Expenses	1.56%	[2]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Global Opportunities Fund | Investor Class | USD ($)	159	493	851	1,857

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 54% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small and micro cap foreign and domestic companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign and domestic companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund may invest a significant portion of its total assets (up to 35% under normal market conditions) in securities of companies with market capitalizations greater than US$5 billion at the time of purchase when the companies meet our investment criteria. The Fund may also invest a significant portion of its total assets in micro cap companies with market capitalizations below US$1 billion (up to 90% under normal market conditions).
The Fund will typically invest in securities issued by companies domiciled in at least three countries, including the United States. The Fund may invest a significant portion of its total assets in companies domiciled in foreign countries (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States). Securities issued by foreign companies incorporated outside the United States whose securities are principally traded in the United States are not defined as “foreign companies” and are not subject to this limitation.
The Fund may invest a significant amount of its total assets (5% to 50% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe are the World’s Best Growth Companies. We travel extensively to visit companies and expect to meet with senior management.
We may also invest in growth companies that we believe have had a temporary setback and therefore have appealing valuation relative to their long-term growth potential.
At times, we may invest in early stage companies with limited or no earnings history if we believe they have outstanding long-term growth potential. We may also invest in initial public offerings (IPOs).
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. We may significantly shift Fund assets between asset classes, sectors, and geographic regions based on where we believe the best growth opportunities and valuations currently exist. The Fund may invest a large percentage of its assets in a few regions or sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Country/Region Risk. Social, political and economic conditions and changes in regulatory, tax, or economic policy in a country or region could significantly affect the market in that country or region. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region might adversely impact the issuers of securities in a different country or region. From time to time, a small number of companies and industries may represent a large portion of the market in a particular country or region, and these companies and industries can be sensitive to adverse social, political, economic, or regulatory developments.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap and Small Company Stock Risk. Micro cap and small company stocks may be very sensitive to changing economic conditions and market downturns because the issuers have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small and micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH GLOBAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	32.73%
Worst — 9/30/2011	-18.94%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Global Opportunities Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Class		3.32%	8.05%	18.48%	Nov. 17, 2008
Investor Class | Return After Taxes on Distributions		0.37%	5.44%	16.24%	Nov. 17, 2008
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		4.26%	6.44%	15.48%	Nov. 17, 2008
MSCI AC World Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	(1.04%)	6.30%	15.44%	Nov. 17, 2008

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Global Opportunities Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH GLOBAL OPPORTUNITIES FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 54% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

54.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small and micro cap foreign and domestic companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign and domestic companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund may invest a significant portion of its total assets (up to 35% under normal market conditions) in securities of companies with market capitalizations greater than US$5 billion at the time of purchase when the companies meet our investment criteria. The Fund may also invest a significant portion of its total assets in micro cap companies with market capitalizations below US$1 billion (up to 90% under normal market conditions).
The Fund will typically invest in securities issued by companies domiciled in at least three countries, including the United States. The Fund may invest a significant portion of its total assets in companies domiciled in foreign countries (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States). Securities issued by foreign companies incorporated outside the United States whose securities are principally traded in the United States are not defined as “foreign companies” and are not subject to this limitation.
The Fund may invest a significant amount of its total assets (5% to 50% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe are the World’s Best Growth Companies. We travel extensively to visit companies and expect to meet with senior management.
We may also invest in growth companies that we believe have had a temporary setback and therefore have appealing valuation relative to their long-term growth potential.
At times, we may invest in early stage companies with limited or no earnings history if we believe they have outstanding long-term growth potential. We may also invest in initial public offerings (IPOs).
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. We may significantly shift Fund assets between asset classes, sectors, and geographic regions based on where we believe the best growth opportunities and valuations currently exist. The Fund may invest a large percentage of its assets in a few regions or sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few regions or sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Country/Region Risk. Social, political and economic conditions and changes in regulatory, tax, or economic policy in a country or region could significantly affect the market in that country or region. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region might adversely impact the issuers of securities in a different country or region. From time to time, a small number of companies and industries may represent a large portion of the market in a particular country or region, and these companies and industries can be sensitive to adverse social, political, economic, or regulatory developments.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap and Small Company Stock Risk. Micro cap and small company stocks may be very sensitive to changing economic conditions and market downturns because the issuers have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small and micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund's Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH GLOBAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	32.73%
Worst — 9/30/2011	-18.94%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Global Opportunities Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.31%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.56%

^[2]

1 Year

rr_ExpenseExampleYear01

$ 159

3 Years

rr_ExpenseExampleYear03

493

5 Years

rr_ExpenseExampleYear05

851

10 Years

rr_ExpenseExampleYear10

$ 1,857

2009

rr_AnnualReturn2009

61.36%

2010

rr_AnnualReturn2010

26.31%

2011

rr_AnnualReturn2011

(8.87%)

2012

rr_AnnualReturn2012

25.50%

2013

rr_AnnualReturn2013

25.27%

2014

rr_AnnualReturn2014

(0.49%)

2015

rr_AnnualReturn2015

3.32%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

32.73%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(18.94%)

1 Year

rr_AverageAnnualReturnYear01

3.32%

5 Years

rr_AverageAnnualReturnYear05

8.05%

Since Inception

rr_AverageAnnualReturnSinceInception

18.48%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Investor Class | Wasatch Global Opportunities Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.37%

5 Years

rr_AverageAnnualReturnYear05

5.44%

Since Inception

rr_AverageAnnualReturnSinceInception

16.24%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Investor Class | Wasatch Global Opportunities Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.26%

5 Years

rr_AverageAnnualReturnYear05

6.44%

Since Inception

rr_AverageAnnualReturnSinceInception

15.48%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Investor Class | Wasatch Global Opportunities Fund | MSCI AC World Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.04%)

^[3]

5 Years

rr_AverageAnnualReturnYear05

6.30%

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

15.44%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

^[3]

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Investor Class | Wasatch International Growth Fund

WASATCH INTERNATIONAL GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch International Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch International Growth Fund Investor Class Shares
Management Fee	1.25%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.25%
Total Annual Fund Operating Expenses	1.50%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch International Growth Fund | Investor Class | USD ($)	153	475	819	1,791

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in foreign growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (5% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH INTERNATIONAL GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	41.88%
Worst — 9/30/2008	-28.61%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch International Growth Fund		1 Year	5 Years	10 Years
Investor Class		15.21%	9.17%	8.17%
Investor Class | Return After Taxes on Distributions		15.21%	9.00%	7.48%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		8.61%	7.25%	6.60%
MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	2.60%	2.63%	4.97%
MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	5.46%	4.39%	4.09%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

**Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Prior to January 31, 2007, the Fund primarily invested in companies with market capitalizations of less than US$2 billion at the time of purchase.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch International Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH INTERNATIONAL GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

46.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in foreign growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (5% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH INTERNATIONAL GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	41.88%
Worst — 9/30/2008	-28.61%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Footnotes

rr_PerformanceTableFootnotesTextBlock

**Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

Investor Class | Wasatch International Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.50%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 153

3 Years

rr_ExpenseExampleYear03

475

5 Years

rr_ExpenseExampleYear05

819

10 Years

rr_ExpenseExampleYear10

$ 1,791

2006

rr_AnnualReturn2006

23.79%

2007

rr_AnnualReturn2007

12.47%

2008

rr_AnnualReturn2008

(53.93%)

2009

rr_AnnualReturn2009

64.19%

2010

rr_AnnualReturn2010

34.24%

2011

rr_AnnualReturn2011

(12.04%)

2012

rr_AnnualReturn2012

33.08%

2013

rr_AnnualReturn2013

26.42%

2014

rr_AnnualReturn2014

(9.05%)

2015

rr_AnnualReturn2015

15.21%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

41.88%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(28.61%)

1 Year

rr_AverageAnnualReturnYear01

15.21%

5 Years

rr_AverageAnnualReturnYear05

9.17%

10 Years

rr_AverageAnnualReturnYear10

8.17%

Investor Class | Wasatch International Growth Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.21%

5 Years

rr_AverageAnnualReturnYear05

9.00%

10 Years

rr_AverageAnnualReturnYear10

7.48%

Investor Class | Wasatch International Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.61%

5 Years

rr_AverageAnnualReturnYear05

7.25%

10 Years

rr_AverageAnnualReturnYear10

6.60%

Investor Class | Wasatch International Growth Fund | MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.60%

^[2]

5 Years

rr_AverageAnnualReturnYear05

2.63%

^[2]

10 Years

rr_AverageAnnualReturnYear10

4.97%

^[2]

Investor Class | Wasatch International Growth Fund | MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.46%

^[2]

5 Years

rr_AverageAnnualReturnYear05

4.39%

^[2]

10 Years

rr_AverageAnnualReturnYear10

4.09%

^[2]

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[2] Prior to January 31, 2007, the Fund primarily invested in companies with market capitalizations of less than US$2 billion at the time of purchase.

XML

Investor Class | Wasatch International Opportunities Fund

WASATCH INTERNATIONAL OPPORTUNITIES FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch International Opportunities Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch International Opportunities Fund Investor Class Shares
Management Fee	1.75%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.48%
Total Annual Fund Operating Expenses	2.23%	[2]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch International Opportunities Fund | Investor Class | USD ($)	226	697	1,194	2,563

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 25% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in foreign micro cap companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$1 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (20% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, health care, industrials, information technology and materials.
The Fund may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH INTERNATIONAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	44.35%
Worst — 9/30/2008	-27.60%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch International Opportunities Fund		1 Year	5 Years	10 Years
Investor Class		9.45%	8.30%	8.47%
Investor Class | Return After Taxes on Distributions		8.26%	6.86%	7.07%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		6.32%	6.48%	6.76%
MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	2.60%	2.63%	4.97%
MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	5.46%	4.39%	4.09%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

[1] Effective January 31, 2016, the management fee was reduced from 1.95% to 1.75%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch International Opportunities Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH INTERNATIONAL OPPORTUNITIES FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 25% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

25.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in foreign micro cap companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$1 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (20% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, health care, industrials, information technology and materials.
The Fund may also invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH INTERNATIONAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	44.35%
Worst — 9/30/2008	-27.60%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Investor Class | Wasatch International Opportunities Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.75%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.48%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.23%

^[2]

1 Year

rr_ExpenseExampleYear01

$ 226

3 Years

rr_ExpenseExampleYear03

697

5 Years

rr_ExpenseExampleYear05

1,194

10 Years

rr_ExpenseExampleYear10

$ 2,563

2006

rr_AnnualReturn2006

31.50%

2007

rr_AnnualReturn2007

15.17%

2008

rr_AnnualReturn2008

(54.73%)

2009

rr_AnnualReturn2009

75.05%

2010

rr_AnnualReturn2010

26.10%

2011

rr_AnnualReturn2011

(16.01%)

2012

rr_AnnualReturn2012

31.79%

2013

rr_AnnualReturn2013

19.33%

2014

rr_AnnualReturn2014

3.07%

2015

rr_AnnualReturn2015

9.45%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

44.35%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.60%)

1 Year

rr_AverageAnnualReturnYear01

9.45%

5 Years

rr_AverageAnnualReturnYear05

8.30%

10 Years

rr_AverageAnnualReturnYear10

8.47%

Investor Class | Wasatch International Opportunities Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.26%

5 Years

rr_AverageAnnualReturnYear05

6.86%

10 Years

rr_AverageAnnualReturnYear10

7.07%

Investor Class | Wasatch International Opportunities Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.32%

5 Years

rr_AverageAnnualReturnYear05

6.48%

10 Years

rr_AverageAnnualReturnYear10

6.76%

Investor Class | Wasatch International Opportunities Fund | MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.60%

^[3]

5 Years

rr_AverageAnnualReturnYear05

2.63%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.97%

^[3]

Investor Class | Wasatch International Opportunities Fund | MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.46%

^[3]

5 Years

rr_AverageAnnualReturnYear05

4.39%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.09%

^[3]

[1] Effective January 31, 2016, the management fee was reduced from 1.95% to 1.75%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.25% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Investor Class | Wasatch Large Cap Value Fund

WASATCH LARGE CAP VALUE FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objectives are to seek capital appreciation and income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Large Cap Value Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Large Cap Value Fund Investor Class Shares
Management Fee	0.90%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.22%
Total Annual Fund Operating Expenses	1.12%
Expense Reimbursement	(0.02%)	[1]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.10%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Large Cap Value Fund | Investor Class | USD ($)	112	354	615	1,361

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies with market capitalizations of over $5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
To achieve the Fund’s investment objectives, the Fund typically invests in the securities of companies that we believe will pay above average dividends or interest, but which remain appropriately valued based on our valuation analysis.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios, such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including consumer staples, energy, financials, health care, industrials, information technology and utilities.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Utilities Sector Risk. The utilities sector can be significantly affected by government regulation, interest rate changes, financing difficulties, supply and demand of services or fuel, intense competition, natural resource conservation, and commodity price fluctuations.

HISTORICAL PERFORMANCE

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Equity Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide information on how the Investor Class of the Fund (and Predecessor Fund for periods prior to December 15, 2008) has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LARGE CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	14.66%
Worst — 12/31/2008	-19.38%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Large Cap Value Fund	1 Year	5 Years	10 Years
Investor Class	(3.13%)	6.50%	5.81%
Investor Class | Return After Taxes on Distributions	(5.55%)	2.90%	3.58%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	0.26%	5.14%	4.60%
Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)	(3.83%)	11.27%	6.16%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.10% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Large Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LARGE CAP VALUE FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objectives are to seek capital appreciation and income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies with market capitalizations of over $5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
To achieve the Fund’s investment objectives, the Fund typically invests in the securities of companies that we believe will pay above average dividends or interest, but which remain appropriately valued based on our valuation analysis.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios, such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including consumer staples, energy, financials, health care, industrials, information technology and utilities.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer staples, energy, financials, health care, industrials, information technology and utilities.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Utilities Sector Risk. The utilities sector can be significantly affected by government regulation, interest rate changes, financing difficulties, supply and demand of services or fuel, intense competition, natural resource conservation, and commodity price fluctuations.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Equity Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide information on how the Investor Class of the Fund (and Predecessor Fund for periods prior to December 15, 2008) has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LARGE CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	14.66%
Worst — 12/31/2008	-19.38%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Large Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.90%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.22%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.12%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.02%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.10%

1 Year

rr_ExpenseExampleYear01

$ 112

3 Years

rr_ExpenseExampleYear03

354

5 Years

rr_ExpenseExampleYear05

615

10 Years

rr_ExpenseExampleYear10

$ 1,361

2006

rr_AnnualReturn2006

20.02%

2007

rr_AnnualReturn2007

12.36%

2008

rr_AnnualReturn2008

(31.14%)

2009

rr_AnnualReturn2009

24.37%

2010

rr_AnnualReturn2010

11.11%

2011

rr_AnnualReturn2011

(3.92%)

2012

rr_AnnualReturn2012

10.55%

2013

rr_AnnualReturn2013

25.78%

2014

rr_AnnualReturn2014

5.85%

2015

rr_AnnualReturn2015

(3.13%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

14.66%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(19.38%)

1 Year

rr_AverageAnnualReturnYear01

(3.13%)

5 Years

rr_AverageAnnualReturnYear05

6.50%

10 Years

rr_AverageAnnualReturnYear10

5.81%

Investor Class | Wasatch Large Cap Value Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.55%)

5 Years

rr_AverageAnnualReturnYear05

2.90%

10 Years

rr_AverageAnnualReturnYear10

3.58%

Investor Class | Wasatch Large Cap Value Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.26%

5 Years

rr_AverageAnnualReturnYear05

5.14%

10 Years

rr_AverageAnnualReturnYear10

4.60%

Investor Class | Wasatch Large Cap Value Fund | Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(3.83%)

5 Years

rr_AverageAnnualReturnYear05

11.27%

10 Years

rr_AverageAnnualReturnYear10

6.16%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.10% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Investor Class | Wasatch Long/Short Fund

WASATCH LONG/SHORT FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is capital appreciation.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Long/Short Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Long/Short Fund Investor Class Shares
Management Fee	1.10%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.20%
Dividend Expense on Short Sales/Interest Expense	0.31%	[1]
Total Annual Fund Operating Expenses	1.61%	[2]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Long/Short Fund | Investor Class | USD ($)	164	508	876	1,911

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets. The Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. We believe opportunities to buy stocks or sell stocks short arise due to a variety of market inefficiencies, including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.

When evaluating long investments, we typically look for stocks that are appropriately valued or undervalued based on our analysis.
When evaluating a short investment, we typically look for signs of current overvaluation. For example, we look for companies that we believe:

• Have earnings that appear to be reflected in the current stock price.
• Are likely to fall short of market expectations.
• Are in industries that exhibit weakness.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.

The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.
The Fund is expected to have a high portfolio turnover rate.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund can make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a fund’s returns or increase volatility.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of fund generally has high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

HISTORICAL PERFORMANCE

The Fund commenced operations on December 15, 2008, upon the reorganization of the 1st Source Monogram Long/Short Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide information on how the Investor Class of the Fund (and Predecessor Fund for periods prior to December 15, 2008) has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk, and to a secondary benchmark (the Citigroup U.S. Domestic 3-Month U.S. Treasury Bills Index), which reflects short-term interest rates and is usually free from the risk of principal fluctuation. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio managers of the Fund, however, were also the portfolio managers of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LONG/SHORT FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	16.00%
Worst — 12/31/2008	-15.94%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Long/Short Fund	1 Year	5 Years	10 Years
Investor Class	(16.22%)	1.49%	3.85%
Investor Class | Return After Taxes on Distributions	(18.19%)	0.61%	2.91%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	(7.53%)	1.21%	2.89%
S&P 500® Index (reflects no deductions for fees, expenses or taxes)	1.38%	12.57%	7.31%
Citigroup U.S. Domestic 3-Month Treasury Bills Index (reflects no deductions for fees, expenses or taxes)	0.03%	0.05%	1.17%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid to brokers varies by security.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.60% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Long/Short Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LONG/SHORT FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

44.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets. The Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. We believe opportunities to buy stocks or sell stocks short arise due to a variety of market inefficiencies, including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.

When evaluating long investments, we typically look for stocks that are appropriately valued or undervalued based on our analysis.
When evaluating a short investment, we typically look for signs of current overvaluation. For example, we look for companies that we believe:

• Have earnings that appear to be reflected in the current stock price.
• Are likely to fall short of market expectations.
• Are in industries that exhibit weakness.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.

The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.
The Fund is expected to have a high portfolio turnover rate.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund can make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a fund’s returns or increase volatility.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of fund generally has high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund commenced operations on December 15, 2008, upon the reorganization of the 1st Source Monogram Long/Short Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide information on how the Investor Class of the Fund (and Predecessor Fund for periods prior to December 15, 2008) has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk, and to a secondary benchmark (the Citigroup U.S. Domestic 3-Month U.S. Treasury Bills Index), which reflects short-term interest rates and is usually free from the risk of principal fluctuation. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio managers of the Fund, however, were also the portfolio managers of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk,

Performance Additional Market Index [Text]

rr_PerformanceAdditionalMarketIndex

The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk, and to a secondary benchmark (the Citigroup U.S. Domestic 3-Month U.S. Treasury Bills Index), which reflects short-term interest rates and is usually free from the risk of principal fluctuation.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LONG/SHORT FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	16.00%
Worst — 12/31/2008	-15.94%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Long/Short Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.10%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Dividend Expense on Short Sales/Interest Expense

rr_Component1OtherExpensesOverAssets

0.31%

^[1]

Other Expenses

rr_OtherExpensesOverAssets

0.20%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.61%

^[2]

1 Year

rr_ExpenseExampleYear01

$ 164

3 Years

rr_ExpenseExampleYear03

508

5 Years

rr_ExpenseExampleYear05

876

10 Years

rr_ExpenseExampleYear10

$ 1,911

2006

rr_AnnualReturn2006

14.72%

2007

rr_AnnualReturn2007

4.98%

2008

rr_AnnualReturn2008

(20.93%)

2009

rr_AnnualReturn2009

30.07%

2010

rr_AnnualReturn2010

9.41%

2011

rr_AnnualReturn2011

1.77%

2012

rr_AnnualReturn2012

8.67%

2013

rr_AnnualReturn2013

18.97%

2014

rr_AnnualReturn2014

(2.33%)

2015

rr_AnnualReturn2015

(16.22%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.00%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.94%)

1 Year

rr_AverageAnnualReturnYear01

(16.22%)

5 Years

rr_AverageAnnualReturnYear05

1.49%

10 Years

rr_AverageAnnualReturnYear10

3.85%

Investor Class | Wasatch Long/Short Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(18.19%)

5 Years

rr_AverageAnnualReturnYear05

0.61%

10 Years

rr_AverageAnnualReturnYear10

2.91%

Investor Class | Wasatch Long/Short Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(7.53%)

5 Years

rr_AverageAnnualReturnYear05

1.21%

10 Years

rr_AverageAnnualReturnYear10

2.89%

Investor Class | Wasatch Long/Short Fund | S&P 500® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.38%

5 Years

rr_AverageAnnualReturnYear05

12.57%

10 Years

rr_AverageAnnualReturnYear10

7.31%

Investor Class | Wasatch Long/Short Fund | Citigroup U.S. Domestic 3-Month Treasury Bills Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.03%

5 Years

rr_AverageAnnualReturnYear05

0.05%

10 Years

rr_AverageAnnualReturnYear10

1.17%

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid to brokers varies by security.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.60% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Wasatch Micro Cap Fund

WASATCH MICRO CAP FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Wasatch Micro Cap Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Wasatch Micro Cap Fund Investor Class Shares
Management Fee	1.75%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.15%
Total Annual Fund Operating Expenses	1.90%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Wasatch Micro Cap Fund | Investor Class | USD ($)	193	597	1,026	2,222

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 31% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in growing micro cap companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of micro-capitalization companies. The Fund considers a company to be a micro-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $1.5 billion or the market capitalization of the largest company in the Russell Microcap Index as of its most recent reconstitution date. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell Microcap Index is $1.33 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We focus on companies that we consider to be high quality, and we use a process of “bottom-up” fundamental analysis to look for companies that we believe have the potential to grow faster than the domestic gross domestic product (GDP) of the United States. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH MICRO CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	27.00%
Worst — 12/31/2008	-31.16%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Wasatch Micro Cap Fund	1 Year	5 Years	10 Years
Investor Class	(1.12%)	8.46%	5.49%
Investor Class | Return After Taxes on Distributions	(4.43%)	7.49%	4.53%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	2.15%	6.69%	4.45%
Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)	(5.16%)	9.23%	5.13%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Wasatch Micro Cap Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH MICRO CAP FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 31% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

31.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in growing micro cap companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of micro-capitalization companies. The Fund considers a company to be a micro-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $1.5 billion or the market capitalization of the largest company in the Russell Microcap Index as of its most recent reconstitution date. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell Microcap Index is $1.33 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We focus on companies that we consider to be high quality, and we use a process of “bottom-up” fundamental analysis to look for companies that we believe have the potential to grow faster than the domestic gross domestic product (GDP) of the United States. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH MICRO CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	27.00%
Worst — 12/31/2008	-31.16%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Micro Cap Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.75%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.15%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.90%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 193

3 Years

rr_ExpenseExampleYear03

597

5 Years

rr_ExpenseExampleYear05

1,026

10 Years

rr_ExpenseExampleYear10

$ 2,222

2006

rr_AnnualReturn2006

17.05%

2007

rr_AnnualReturn2007

2.23%

2008

rr_AnnualReturn2008

(49.29%)

2009

rr_AnnualReturn2009

44.37%

2010

rr_AnnualReturn2010

29.76%

2011

rr_AnnualReturn2011

(6.39%)

2012

rr_AnnualReturn2012

11.85%

2013

rr_AnnualReturn2013

44.70%

2014

rr_AnnualReturn2014

0.17%

2015

rr_AnnualReturn2015

(1.12%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

27.00%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(31.16%)

1 Year

rr_AverageAnnualReturnYear01

(1.12%)

5 Years

rr_AverageAnnualReturnYear05

8.46%

10 Years

rr_AverageAnnualReturnYear10

5.49%

Wasatch Micro Cap Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.43%)

5 Years

rr_AverageAnnualReturnYear05

7.49%

10 Years

rr_AverageAnnualReturnYear10

4.53%

Wasatch Micro Cap Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.15%

5 Years

rr_AverageAnnualReturnYear05

6.69%

10 Years

rr_AverageAnnualReturnYear10

4.45%

Wasatch Micro Cap Fund | Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.16%)

5 Years

rr_AverageAnnualReturnYear05

9.23%

10 Years

rr_AverageAnnualReturnYear10

5.13%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Wasatch Micro Cap Value Fund

WASATCH MICRO CAP VALUE FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Wasatch Micro Cap Value Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Wasatch Micro Cap Value Fund Investor Class Shares
Management Fee	1.75%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.26%
Interest Expense	0.01%
Acquired Fund Fees and Expenses	0.07%
Total Annual Fund Operating Expenses	2.09%	[1]
Expense Reimbursement	(0.06%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	2.03%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Wasatch Micro Cap Value Fund | Investor Class | USD ($)	206	649	1,118	2,416

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 53% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in micro cap companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of micro-capitalization companies. The Fund considers a company to be a micro-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $1.5 billion or the market capitalization of the largest company in the Russell Microcap Index as of its most recent reconstitution date. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell Microcap Index is $1.33 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may invest in initial public offerings (IPOs).
While the Fund primarily invests in value companies, it may also invest in growth companies if the Advisor believes that a company’s current valuation is at a sufficient discount to its projected long term earnings growth rate.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Value Momentum — Valuation that is inexpensive relative to history, but catalyst for future growth has been identified.

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH MICRO CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	40.00%
Worst — 12/31/2008	-26.67%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Wasatch Micro Cap Value Fund	1 Year	5 Years	10 Years
Investor Class	7.19%	10.76%	9.52%
Investor Class | Return After Taxes on Distributions	4.28%	8.26%	7.56%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	6.18%	8.45%	7.57%
Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)	(5.16%)	9.23%	5.13%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Wasatch Micro Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH MICRO CAP VALUE FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 53% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

53.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund’s most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in micro cap companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of micro-capitalization companies. The Fund considers a company to be a micro-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $1.5 billion or the market capitalization of the largest company in the Russell Microcap Index as of its most recent reconstitution date. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell Microcap Index is $1.33 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may invest in initial public offerings (IPOs).
While the Fund primarily invests in value companies, it may also invest in growth companies if the Advisor believes that a company’s current valuation is at a sufficient discount to its projected long term earnings growth rate.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Value Momentum — Valuation that is inexpensive relative to history, but catalyst for future growth has been identified.

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH MICRO CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns

Best — 6/30/2009	40.00%
Worst — 12/31/2008	-26.67%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Micro Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.75%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Interest Expense

rr_Component2OtherExpensesOverAssets

0.01%

Other Expenses

rr_OtherExpensesOverAssets

0.26%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.07%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.09%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.06%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

2.03%

1 Year

rr_ExpenseExampleYear01

$ 206

3 Years

rr_ExpenseExampleYear03

649

5 Years

rr_ExpenseExampleYear05

1,118

10 Years

rr_ExpenseExampleYear10

$ 2,416

2006

rr_AnnualReturn2006

28.83%

2007

rr_AnnualReturn2007

7.02%

2008

rr_AnnualReturn2008

(47.20%)

2009

rr_AnnualReturn2009

70.40%

2010

rr_AnnualReturn2010

20.09%

2011

rr_AnnualReturn2011

(10.41%)

2012

rr_AnnualReturn2012

22.10%

2013

rr_AnnualReturn2013

43.23%

2014

rr_AnnualReturn2014

(0.75%)

2015

rr_AnnualReturn2015

7.19%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

40.00%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(26.67%)

1 Year

rr_AverageAnnualReturnYear01

7.19%

5 Years

rr_AverageAnnualReturnYear05

10.76%

10 Years

rr_AverageAnnualReturnYear10

9.52%

Wasatch Micro Cap Value Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.28%

5 Years

rr_AverageAnnualReturnYear05

8.26%

10 Years

rr_AverageAnnualReturnYear10

7.56%

Wasatch Micro Cap Value Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.18%

5 Years

rr_AverageAnnualReturnYear05

8.45%

10 Years

rr_AverageAnnualReturnYear10

7.57%

Wasatch Micro Cap Value Fund | Russell Microcap® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.16%)

5 Years

rr_AverageAnnualReturnYear05

9.23%

10 Years

rr_AverageAnnualReturnYear10

5.13%

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Investor Class | Wasatch Small Cap Growth Fund

WASATCH SMALL CAP GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Small Cap Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Small Cap Growth Fund Investor Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.22%
Total Annual Fund Operating Expenses	1.22%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Small Cap Growth Fund | Investor Class | USD ($)	124	387	670	1,477

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 31% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small growth companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
Within the Fund’s portfolio, we seek to create a blend of “core” companies that we believe have the potential to grow steadily over long periods of time at faster rates than average large companies, and “high growth” companies that we believe have the potential to grow faster and more aggressively than core companies. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe have superior growth prospects. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	25.04%
Worst — 12/31/2008	-22.04%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Small Cap Growth Fund	1 Year	5 Years	10 Years
Investor Class	(0.55%)	9.36%	7.47%
Investor Class | Return After Taxes on Distributions	(4.19%)	7.58%	6.29%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	2.77%	7.50%	6.12%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	(1.38%)	10.67%	7.95%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	(4.41%)	9.19%	6.80%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Small Cap Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 31% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

31.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small growth companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
Within the Fund’s portfolio, we seek to create a blend of “core” companies that we believe have the potential to grow steadily over long periods of time at faster rates than average large companies, and “high growth” companies that we believe have the potential to grow faster and more aggressively than core companies. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe have superior growth prospects. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund's performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund's Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH SMALL CAP GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	25.04%
Worst — 12/31/2008	-22.04%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund's returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Small Cap Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.22%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.22%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 124

3 Years

rr_ExpenseExampleYear03

387

5 Years

rr_ExpenseExampleYear05

670

10 Years

rr_ExpenseExampleYear10

$ 1,477

2006

rr_AnnualReturn2006

8.40%

2007

rr_AnnualReturn2007

8.36%

2008

rr_AnnualReturn2008

(41.66%)

2009

rr_AnnualReturn2009

48.74%

2010

rr_AnnualReturn2010

28.92%

2011

rr_AnnualReturn2011

(0.06%)

2012

rr_AnnualReturn2012

16.95%

2013

rr_AnnualReturn2013

31.17%

2014

rr_AnnualReturn2014

2.61%

2015

rr_AnnualReturn2015

(0.55%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

25.04%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(22.04%)

1 Year

rr_AverageAnnualReturnYear01

(0.55%)

5 Years

rr_AverageAnnualReturnYear05

9.36%

10 Years

rr_AverageAnnualReturnYear10

7.47%

Investor Class | Wasatch Small Cap Growth Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.19%)

5 Years

rr_AverageAnnualReturnYear05

7.58%

10 Years

rr_AverageAnnualReturnYear10

6.29%

Investor Class | Wasatch Small Cap Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.77%

5 Years

rr_AverageAnnualReturnYear05

7.50%

10 Years

rr_AverageAnnualReturnYear10

6.12%

Investor Class | Wasatch Small Cap Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.38%)

5 Years

rr_AverageAnnualReturnYear05

10.67%

10 Years

rr_AverageAnnualReturnYear10

7.95%

Investor Class | Wasatch Small Cap Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.41%)

5 Years

rr_AverageAnnualReturnYear05

9.19%

10 Years

rr_AverageAnnualReturnYear10

6.80%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Investor Class | Wasatch Small Cap Value Fund

WASATCH SMALL CAP VALUE FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch Small Cap Value Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch Small Cap Value Fund Investor Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.21%
Total Annual Fund Operating Expenses	1.21%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch Small Cap Value Fund | Investor Class | USD ($)	123	384	665	1,465

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 57% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate. The Fund’s secondary objective of income is achieved when portfolio companies pay dividends.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	33.91%
Worst — 12/31/2008	-34.04%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch Small Cap Value Fund	1 Year	5 Years	10 Years
Investor Class	none	10.33%	6.41%
Investor Class | Return After Taxes on Distributions	(0.12%)	10.30%	5.57%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	0.10%	8.21%	5.03%
Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)	(7.47%)	7.67%	5.57%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	(4.41%)	9.19%	6.80%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch Small Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP VALUE FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 57% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

57.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate. The Fund’s secondary objective of income is achieved when portfolio companies pay dividends.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH SMALL CAP VALUE FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	33.91%
Worst — 12/31/2008	-34.04%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch Small Cap Value Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.21%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.21%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 123

3 Years

rr_ExpenseExampleYear03

384

5 Years

rr_ExpenseExampleYear05

665

10 Years

rr_ExpenseExampleYear10

$ 1,465

2006

rr_AnnualReturn2006

14.84%

2007

rr_AnnualReturn2007

(3.00%)

2008

rr_AnnualReturn2008

(47.75%)

2009

rr_AnnualReturn2009

55.91%

2010

rr_AnnualReturn2010

25.52%

2011

rr_AnnualReturn2011

(5.22%)

2012

rr_AnnualReturn2012

16.52%

2013

rr_AnnualReturn2013

37.81%

2014

rr_AnnualReturn2014

7.40%

2015

rr_AnnualReturn2015

none

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

33.91%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(34.04%)

1 Year

rr_AverageAnnualReturnYear01

none

5 Years

rr_AverageAnnualReturnYear05

10.33%

10 Years

rr_AverageAnnualReturnYear10

6.41%

Investor Class | Wasatch Small Cap Value Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(0.12%)

5 Years

rr_AverageAnnualReturnYear05

10.30%

10 Years

rr_AverageAnnualReturnYear10

5.57%

Investor Class | Wasatch Small Cap Value Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.10%

5 Years

rr_AverageAnnualReturnYear05

8.21%

10 Years

rr_AverageAnnualReturnYear10

5.03%

Investor Class | Wasatch Small Cap Value Fund | Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(7.47%)

5 Years

rr_AverageAnnualReturnYear05

7.67%

10 Years

rr_AverageAnnualReturnYear10

5.57%

Investor Class | Wasatch Small Cap Value Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.41%)

5 Years

rr_AverageAnnualReturnYear05

9.19%

10 Years

rr_AverageAnnualReturnYear10

6.80%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Wasatch Strategic Income Fund

WASATCH STRATEGIC INCOME FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is to capture current income.

A secondary objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Wasatch Strategic Income Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Wasatch Strategic Income Fund Investor Class Shares
Management Fee	0.70%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.25%
Acquired Fund Fees and Expenses	0.56%
Total Annual Fund Operating Expenses	1.51%	[1]
Expense Reimbursement	none	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.51%

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Wasatch Strategic Income Fund | Investor Class | USD ($)	154	478	824	1,801

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 78% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in income-producing securities.
Under normal market conditions, we will invest the Fund’s assets in income-producing domestic and foreign securities, including equity securities and fixed income securities of companies of all market capitalizations. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund is not managed as a balanced portfolio. At times, one type of security may make up a substantial portion of the Fund, while other types may have minimal or no representation.
The Fund may invest its assets in securities issued by foreign companies in developed countries without limit. To a lesser extent, the Fund may invest in foreign companies in emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies.
In our search for investments, we maintain the flexibility to invest in companies from a variety of industries. The Fund, however, does have a concentration in the financials sector — meaning that at least 25% of the Fund’s total assets will be invested in securities of issuers in the group of industries in the financials sector. For both domestic and foreign securities, we define the group of industries comprising the financials sector to include, among others, Banks (Commercial Banks, Thrifts and Mortgage Finance), Diversified Financial Companies (Diversified Financial Services, Consumer Finance, Capital Markets), Finance Companies, Financial Data Processing Services and Systems, Finance Companies (Small Loan), Financial Information Services, Insurance Companies (Life, Multi-Line, Property-Casualty), Investment Management Companies, Real Estate Companies (Real Estate Investment Trusts [REITs], Real Estate Management and Development Companies), Rental and Leasing Services (Commercial), Savings and Loans, and Securities Brokerage and Services.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, industrials and information technology.
The Fund may invest in exchange-traded funds (ETFs).
The Fund may make short sales of securities, and may also use derivatives such as put and call options and futures contracts for hedging and non-hedging purposes. The Fund may write put and call options subject to applicable law and SEC guidelines.
In the selection of equity securities, we use “bottom-up” fundamental analysis to identify individual companies with attractive, sustainable dividend yields or the potential for dividend growth. In certain situations, the Fund may acquire non-income producing securities if we believe the company has the potential to pay dividends in the future. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
Characteristics we consider when investing in equity securities generally include:

• Attractive, sustainable dividend yields or the potential for dividend growth.
• Experienced top management.
• Sustainable competitive advantage.
• Stable demand for products and services.
• Ability to capitalize on favorable long-term trends.

The Fund’s investments in fixed income securities may include domestic and foreign corporate bonds with a variety of maturities (e.g., long-term, intermediate or short-term) and credit qualities (e.g., investment grade or non-investment grade). At certain times the Fund may emphasize one particular maturity or credit quality. The Fund may invest in non-investment grade securities without limitation. The Fund may also invest in U.S. Treasury securities and the debt obligations of foreign governments.
Characteristics we consider when investing in fixed income securities generally include:

• Rates of current income.
• Credit quality of the issuer.
• Maturity, duration and other characteristics of the obligation.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Short Sales Risk. The Fund can make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a fund’s returns or increase volatility.
Investment Companies Risk. The Fund may invest in the shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, unit investment trusts and exchange-traded funds. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, the Fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Fund shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Exchange-Traded Funds (ETFs) Risk. ETFs are investment companies that are bought and sold on a securities exchange. Shares of ETFs are redeemable only in larger aggregations of a specified number of shares and generally on an in-kind basis. When the Fund invests in an ETF, it will bear additional expenses based on its pro rata share of the ETF’s operating expenses. In addition, the Fund will incur brokerage costs when purchasing and selling shares of ETFs. The risk of owning an ETF generally reflects the risks of the underlying securities held by the ETF and investment strategies employed by such ETF (such as the use of leverage). The market price may also fluctuate due to the supply of and demand for the ETF’s shares on the exchange upon which its shares are traded. Lack of liquidity in an ETF could result in the ETF being more volatile than the underlying portfolio of securities. In addition, because of ETF expenses, compared to owning the underlying securities directly, it may be more costly to own an ETF.
REIT Risk. Investments in real estate investment trusts (REITs) subject the Fund to risks associated with the direct ownership of real estate. The value of REIT securities can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements and the management skill and creditworthiness of the issuer. In addition, the value of a REIT can depend on the structure and cash flow generated by the REIT and REITs may not have diversified holdings. Because REITs are pooled investment vehicles that have expenses of their own, the Fund will indirectly bear its proportionate share of those expenses.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based stock market index composed of securities similar to those held by the Fund and an additional broad-based bond market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH STRATEGIC INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	21.21%
Worst — 12/31/2008	-28.22%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Wasatch Strategic Income Fund	1 Year	5 Years	Since Inception	Inception Date
Investor Class	(10.95%)	9.73%	6.26%	Feb. 01, 2006
Investor Class | Return After Taxes on Distributions	(12.85%)	8.26%	4.39%	Feb. 01, 2006
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	(5.12%)	7.48%	4.34%	Feb. 01, 2006
S&P 500® Index (reflects no deductions for fees, expenses or taxes)	1.38%	12.57%	7.09%	Feb. 01, 2006
Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)	0.55%	3.25%	4.55%	Feb. 01, 2006

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date. The Fund's reimbursement was less than 0.01%.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Wasatch Strategic Income Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH STRATEGIC INCOME FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is to capture current income.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

A secondary objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 78% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

78.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in income-producing securities.
Under normal market conditions, we will invest the Fund’s assets in income-producing domestic and foreign securities, including equity securities and fixed income securities of companies of all market capitalizations. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund is not managed as a balanced portfolio. At times, one type of security may make up a substantial portion of the Fund, while other types may have minimal or no representation.
The Fund may invest its assets in securities issued by foreign companies in developed countries without limit. To a lesser extent, the Fund may invest in foreign companies in emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies.
In our search for investments, we maintain the flexibility to invest in companies from a variety of industries. The Fund, however, does have a concentration in the financials sector — meaning that at least 25% of the Fund’s total assets will be invested in securities of issuers in the group of industries in the financials sector. For both domestic and foreign securities, we define the group of industries comprising the financials sector to include, among others, Banks (Commercial Banks, Thrifts and Mortgage Finance), Diversified Financial Companies (Diversified Financial Services, Consumer Finance, Capital Markets), Finance Companies, Financial Data Processing Services and Systems, Finance Companies (Small Loan), Financial Information Services, Insurance Companies (Life, Multi-Line, Property-Casualty), Investment Management Companies, Real Estate Companies (Real Estate Investment Trusts [REITs], Real Estate Management and Development Companies), Rental and Leasing Services (Commercial), Savings and Loans, and Securities Brokerage and Services.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, industrials and information technology.
The Fund may invest in exchange-traded funds (ETFs).
The Fund may make short sales of securities, and may also use derivatives such as put and call options and futures contracts for hedging and non-hedging purposes. The Fund may write put and call options subject to applicable law and SEC guidelines.
In the selection of equity securities, we use “bottom-up” fundamental analysis to identify individual companies with attractive, sustainable dividend yields or the potential for dividend growth. In certain situations, the Fund may acquire non-income producing securities if we believe the company has the potential to pay dividends in the future. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
Characteristics we consider when investing in equity securities generally include:

• Attractive, sustainable dividend yields or the potential for dividend growth.
• Experienced top management.
• Sustainable competitive advantage.
• Stable demand for products and services.
• Ability to capitalize on favorable long-term trends.

The Fund’s investments in fixed income securities may include domestic and foreign corporate bonds with a variety of maturities (e.g., long-term, intermediate or short-term) and credit qualities (e.g., investment grade or non-investment grade). At certain times the Fund may emphasize one particular maturity or credit quality. The Fund may invest in non-investment grade securities without limitation. The Fund may also invest in U.S. Treasury securities and the debt obligations of foreign governments.
Characteristics we consider when investing in fixed income securities generally include:

• Rates of current income.
• Credit quality of the issuer.
• Maturity, duration and other characteristics of the obligation.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund, however, does have a concentration in the financials sector — meaning that at least 25% of the Fund’s total assets will be invested in securities of issuers in the group of industries in the financials sector. For both domestic and foreign securities, we define the group of industries comprising the financials sector to include, among others, Banks (Commercial Banks, Thrifts and Mortgage Finance), Diversified Financial Companies (Diversified Financial Services, Consumer Finance, Capital Markets), Finance Companies, Financial Data Processing Services and Systems, Finance Companies (Small Loan), Financial Information Services, Insurance Companies (Life, Multi-Line, Property-Casualty), Investment Management Companies, Real Estate Companies (Real Estate Investment Trusts [REITs], Real Estate Management and Development Companies), Rental and Leasing Services (Commercial), Savings and Loans, and Securities Brokerage and Services.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Short Sales Risk. The Fund can make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a fund’s returns or increase volatility.
Investment Companies Risk. The Fund may invest in the shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, unit investment trusts and exchange-traded funds. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, the Fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Fund shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Exchange-Traded Funds (ETFs) Risk. ETFs are investment companies that are bought and sold on a securities exchange. Shares of ETFs are redeemable only in larger aggregations of a specified number of shares and generally on an in-kind basis. When the Fund invests in an ETF, it will bear additional expenses based on its pro rata share of the ETF’s operating expenses. In addition, the Fund will incur brokerage costs when purchasing and selling shares of ETFs. The risk of owning an ETF generally reflects the risks of the underlying securities held by the ETF and investment strategies employed by such ETF (such as the use of leverage). The market price may also fluctuate due to the supply of and demand for the ETF’s shares on the exchange upon which its shares are traded. Lack of liquidity in an ETF could result in the ETF being more volatile than the underlying portfolio of securities. In addition, because of ETF expenses, compared to owning the underlying securities directly, it may be more costly to own an ETF.
REIT Risk. Investments in real estate investment trusts (REITs) subject the Fund to risks associated with the direct ownership of real estate. The value of REIT securities can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements and the management skill and creditworthiness of the issuer. In addition, the value of a REIT can depend on the structure and cash flow generated by the REIT and REITs may not have diversified holdings. Because REITs are pooled investment vehicles that have expenses of their own, the Fund will indirectly bear its proportionate share of those expenses.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

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HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

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The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based stock market index composed of securities similar to those held by the Fund and an additional broad-based bond market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based stock market index composed of securities similar to those held by the Fund and an additional broad-based bond market index.

Performance Availability Website Address [Text]

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www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

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The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH STRATEGIC INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns

Best — 6/30/2009	21.21%
Worst — 12/31/2008	-28.22%

Performance Table Heading

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Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

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The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

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After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Strategic Income Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.70%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.25%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.56%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.51%

^[1]

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.51%

1 Year

rr_ExpenseExampleYear01

$ 154

3 Years

rr_ExpenseExampleYear03

478

5 Years

rr_ExpenseExampleYear05

824

10 Years

rr_ExpenseExampleYear10

$ 1,801

2007

rr_AnnualReturn2007

(2.02%)

2008

rr_AnnualReturn2008

(40.57%)

2009

rr_AnnualReturn2009

38.04%

2010

rr_AnnualReturn2010

19.87%

2011

rr_AnnualReturn2011

6.35%

2012

rr_AnnualReturn2012

11.29%

2013

rr_AnnualReturn2013

33.25%

2014

rr_AnnualReturn2014

13.25%

2015

rr_AnnualReturn2015

(10.95%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

21.21%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(28.22%)

1 Year

rr_AverageAnnualReturnYear01

(10.95%)

5 Years

rr_AverageAnnualReturnYear05

9.73%

Since Inception

rr_AverageAnnualReturnSinceInception

6.26%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(12.85%)

5 Years

rr_AverageAnnualReturnYear05

8.26%

Since Inception

rr_AverageAnnualReturnSinceInception

4.39%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.12%)

5 Years

rr_AverageAnnualReturnYear05

7.48%

Since Inception

rr_AverageAnnualReturnSinceInception

4.34%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | S&P 500® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.38%

5 Years

rr_AverageAnnualReturnYear05

12.57%

Since Inception

rr_AverageAnnualReturnSinceInception

7.09%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

Wasatch Strategic Income Fund | Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.55%

5 Years

rr_AverageAnnualReturnYear05

3.25%

Since Inception

rr_AverageAnnualReturnSinceInception

4.55%

Inception Date

rr_AverageAnnualReturnInceptionDate

Feb. 01, 2006

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date. The Fund's reimbursement was less than 0.01%.

XML

Wasatch Ultra Growth Fund

WASATCH ULTRA GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Wasatch Ultra Growth Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Wasatch Ultra Growth Fund Investor Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.31%
Acquired Fund Fees and Expenses	0.07%
Total Annual Fund Operating Expenses	1.38%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Wasatch Ultra Growth Fund | Investor Class | USD ($)	140	437	755	1,657

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 38% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in smaller high growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies which we consider to be rapidly growing. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We use a process of “bottom-up” fundamental analysis to look for individual companies that we believe have above average potential for rapid earnings growth and stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH ULTRA GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	28.60%
Worst — 12/31/2008	-31.56%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Wasatch Ultra Growth Fund	1 Year	5 Years	10 Years
Investor Class	2.85%	8.96%	5.95%
Investor Class | Return After Taxes on Distributions	0.83%	6.19%	4.20%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	3.33%	7.14%	4.78%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	(1.38%)	10.67%	7.95%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Wasatch Ultra Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH ULTRA GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 38% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

38.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in smaller high growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies which we consider to be rapidly growing. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). These companies are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 30% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We use a process of “bottom-up” fundamental analysis to look for individual companies that we believe have above average potential for rapid earnings growth and stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH ULTRA GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	28.60%
Worst — 12/31/2008	-31.56%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch Ultra Growth Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.31%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.07%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.38%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 140

3 Years

rr_ExpenseExampleYear03

437

5 Years

rr_ExpenseExampleYear05

755

10 Years

rr_ExpenseExampleYear10

$ 1,657

2006

rr_AnnualReturn2006

7.31%

2007

rr_AnnualReturn2007

15.11%

2008

rr_AnnualReturn2008

(55.40%)

2009

rr_AnnualReturn2009

55.01%

2010

rr_AnnualReturn2010

35.85%

2011

rr_AnnualReturn2011

(5.37%)

2012

rr_AnnualReturn2012

12.45%

2013

rr_AnnualReturn2013

35.67%

2014

rr_AnnualReturn2014

3.44%

2015

rr_AnnualReturn2015

2.85%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

28.60%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(31.56%)

1 Year

rr_AverageAnnualReturnYear01

2.85%

5 Years

rr_AverageAnnualReturnYear05

8.96%

10 Years

rr_AverageAnnualReturnYear10

5.95%

Wasatch Ultra Growth Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.83%

5 Years

rr_AverageAnnualReturnYear05

6.19%

10 Years

rr_AverageAnnualReturnYear10

4.20%

Wasatch Ultra Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.33%

5 Years

rr_AverageAnnualReturnYear05

7.14%

10 Years

rr_AverageAnnualReturnYear10

4.78%

Wasatch Ultra Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.38%)

5 Years

rr_AverageAnnualReturnYear05

10.67%

10 Years

rr_AverageAnnualReturnYear10

7.95%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Investor Class | Wasatch World Innovators Fund

WASATCH WORLD INNOVATORS FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Investor Class Wasatch World Innovators Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Investor Class Wasatch World Innovators Fund Investor Class Shares
Management Fee	1.50%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.26%
Total Annual Fund Operating Expenses	1.76%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Investor Class | Wasatch World Innovators Fund | Investor Class | USD ($)	179	555	955	2,075

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 100% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in domestic and foreign growth companies that we believe are innovators in their respective sectors or industries.
Modern innovative companies have global business models that are less dependent upon their place of domicile, the location of their headquarters, or the exchange on which their stocks are listed. Under normal market conditions, the Fund will typically be invested in at least three developed countries, including the U.S. The Fund may invest in securities issued by companies domiciled in emerging and frontier markets without limitation.
Under normal market conditions, we expect that a significant portion of the Fund’s assets will be invested in equity securities of companies that have significant non-U.S. economic risk exposure. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). We will consider a company to have significant non-U.S. economic risk exposure if, at the time of purchase, it has at least 50% of its assets outside the U.S., or if at least 50% of its revenues or profits are from goods produced or sold, investments made, or services performed outside the U.S. The Fund may invest a significant portion of its total assets in companies domiciled in foreign companies (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States).
We will use a process of “bottom-up” fundamental analysis to invest in companies of any size. However, because innovative companies are rapidly evolving, we expect to invest a significant portion of the Fund’s assets in early stage companies and small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We have defined two broad categories that we believe are critical to identifying companies with outstanding investment potential. The first is companies that possess valuable intellectual property. The second is companies that are innovators in their respective sectors or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com. Effective April 1, 2011, the Wasatch World Innovators Fund changed its name from the Wasatch Global Science & Technology Fund and changed its principal strategies and primary comparison benchmark index. The bar chart, best and worst quarterly returns and average annual total return table include performance prior to these changes.

WASATCH WORLD INNOVATORS FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	27.41%
Worst — 12/31/2008	-30.07%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Investor Class - Wasatch World Innovators Fund		1 Year	5 Years	10 Years
Investor Class		6.20%	11.03%	8.11%
Investor Class | Return After Taxes on Distributions		3.15%	9.54%	7.10%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		6.09%	8.77%	6.55%
MSCI AC World Investable Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(2.19%)	6.11%	4.99%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Investor Class | Wasatch World Innovators Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH WORLD INNOVATORS FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 100% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

100.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in domestic and foreign growth companies that we believe are innovators in their respective sectors or industries.
Modern innovative companies have global business models that are less dependent upon their place of domicile, the location of their headquarters, or the exchange on which their stocks are listed. Under normal market conditions, the Fund will typically be invested in at least three developed countries, including the U.S. The Fund may invest in securities issued by companies domiciled in emerging and frontier markets without limitation.
Under normal market conditions, we expect that a significant portion of the Fund’s assets will be invested in equity securities of companies that have significant non-U.S. economic risk exposure. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). We will consider a company to have significant non-U.S. economic risk exposure if, at the time of purchase, it has at least 50% of its assets outside the U.S., or if at least 50% of its revenues or profits are from goods produced or sold, investments made, or services performed outside the U.S. The Fund may invest a significant portion of its total assets in companies domiciled in foreign companies (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States).
We will use a process of “bottom-up” fundamental analysis to invest in companies of any size. However, because innovative companies are rapidly evolving, we expect to invest a significant portion of the Fund’s assets in early stage companies and small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We have defined two broad categories that we believe are critical to identifying companies with outstanding investment potential. The first is companies that possess valuable intellectual property. The second is companies that are innovators in their respective sectors or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com. Effective April 1, 2011, the Wasatch World Innovators Fund changed its name from the Wasatch Global Science & Technology Fund and changed its principal strategies and primary comparison benchmark index. The bar chart, best and worst quarterly returns and average annual total return table include performance prior to these changes.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH WORLD INNOVATORS FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	27.41%
Worst — 12/31/2008	-30.07%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Investor Class | Wasatch World Innovators Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.26%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.76%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 179

3 Years

rr_ExpenseExampleYear03

555

5 Years

rr_ExpenseExampleYear05

955

10 Years

rr_ExpenseExampleYear10

$ 2,075

2006

rr_AnnualReturn2006

15.95%

2007

rr_AnnualReturn2007

13.17%

2008

rr_AnnualReturn2008

(52.75%)

2009

rr_AnnualReturn2009

67.48%

2010

rr_AnnualReturn2010

24.46%

2011

rr_AnnualReturn2011

4.53%

2012

rr_AnnualReturn2012

18.04%

2013

rr_AnnualReturn2013

33.70%

2014

rr_AnnualReturn2014

(3.68%)

2015

rr_AnnualReturn2015

6.20%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

27.41%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(30.07%)

1 Year

rr_AverageAnnualReturnYear01

6.20%

5 Years

rr_AverageAnnualReturnYear05

11.03%

10 Years

rr_AverageAnnualReturnYear10

8.11%

Investor Class | Wasatch World Innovators Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.15%

5 Years

rr_AverageAnnualReturnYear05

9.54%

10 Years

rr_AverageAnnualReturnYear10

7.10%

Investor Class | Wasatch World Innovators Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.09%

5 Years

rr_AverageAnnualReturnYear05

8.77%

10 Years

rr_AverageAnnualReturnYear10

6.55%

Investor Class | Wasatch World Innovators Fund | MSCI AC World Investable Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(2.19%)

^[2]

5 Years

rr_AverageAnnualReturnYear05

6.11%

^[2]

10 Years

rr_AverageAnnualReturnYear10

4.99%

^[2]

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[2] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Wasatch-1st Source Income Fund

WASATCH-1ST SOURCE INCOME FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is to seek current income consistent with the preservation of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Wasatch-1st Source Income Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Wasatch-1st Source Income Fund Investor Class Shares
Management Fee	0.55%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.17%
Acquired Fund Fees and Expenses	0.01%
Total Annual Fund Operating Expenses	0.73%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Wasatch-1st Source Income Fund | Investor Class | USD ($)	75	234	407	908

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund normally invests at least 65% of its total assets in debt securities of all types, including corporate bonds, U.S. government bonds, and variable and floating rate securities.
Consistent with the Wasatch-1st Source Income Fund’s (Income Fund) investment objective, 1st Source Corporation Investment Advisors, Inc. (1st Source), the Fund’s Sub-Advisor, expects the Fund to:

• Invest substantially all, but in no event less than 65%, of the Fund’s total assets at the time of purchase in debt securities.
• Invest in fixed income securities consisting of bonds, fixed income preferred stocks, debentures, notes, zero-coupon securities, mortgage-related and other asset-backed securities, state, municipal or industrial revenue bonds, obligations issued or guaranteed by agencies or instrumentalities of the U.S. government, debt securities convertible into or exchangeable for common stocks, foreign debt securities, income participation loans, guaranteed investment contracts, first mortgage loans and participation certificates in pools of mortgages issued or guaranteed by agencies or instrumentalities of the U.S. government.
• Typically invest in debt securities rated at the time of purchase within the four highest rating categories assigned by one or more nationally recognized statistical rating organizations (NRSROs) or, if unrated, those which 1st Source deems to be of comparable quality. The Fund may also invest up to 10% of its total assets in non-investment grade debt securities.

The Fund may engage in repurchase transactions, credit default swaps, forward contracts, and may also engage in futures transactions solely for hedging purposes, and may invest in options on futures. The Fund may also invest in other investment companies.
The Fund may purchase securities on a when-issued or delayed delivery basis, in which a security’s price and yield are fixed on a specific date, but payment and delivery are scheduled for a future date beyond the standard settlement period.
It is anticipated that the Fund will have an average maturity of 3-1/2 years to 5 years and an effective duration of 2-1/2 years to 4-1/2 years.
The Fund may invest a large percentage of its assets in a few sectors, including financials and heath care.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.
Convertible Securities Risk. The Fund may invest in convertible securities, which are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and have less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security then the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Ratings Agency Risk. Credit quality in the high yield securities market can change suddenly and unexpectedly, and even recently issued credit ratings may not fully reflect the actual risks posed by a particular high yield security. For these reasons, it is generally the policy of 1st Source not to rely exclusively on ratings issued by established NRSROs, but to supplement such ratings with its own independent and ongoing review of credit quality. The achievement of the Fund’s investment objective by investments in such securities may be more dependent on 1st Source’s credit analysis than is the case for higher quality bonds. Should the rating of a portfolio security be downgraded, 1st Source will determine whether it is in the best interests of the Fund to retain or dispose of such security.
Repurchase Agreements Risk. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
When-Issued Securities Risk. The Fund may purchase securities on a “when-issued” basis (i.e., for delivery beyond the normal settlement date at a stated price and yield). When the Fund engages in “when-issued” transactions, it relies on the seller to consummate the trade. Failure of the seller to do so may result in the Fund incurring a loss or missing the opportunity to obtain a price considered to be advantageous. The Fund will engage in “when-issued” delivery transactions only for the purpose of acquiring portfolio securities consistent with the Fund’s investment objective and strategies and not for investment leverage.
Investment Companies Risk. The Fund may invest in the shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, unit investment trusts and exchange-traded funds. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, the Fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Fund shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Credit Default Swaps Risk. The Fund may enter into credit default swaps, interest rate swaps and currency swaps. Swap agreements will tend to shift a fund’s investment exposure from one type of investment to another. Depending on how they are used, swap agreements may increase or decrease the overall volatility of the Fund’s portfolio and its share price and yield. Swaps are subject to counterparty risk. The Fund bears the loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. For this reason, the Fund will enter into swap agreements only with counterparties that meet certain standards of creditworthiness.
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.

HISTORICAL PERFORMANCE

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide information on how the Investor Class of the Fund (and Predecessor Fund for periods prior to December 15, 2008) has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based bond market index. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio manager of the Fund, however, was also the portfolio manager of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH-1ST SOURCE INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 9/30/2006	2.85%
Worst — 6/30/2013	-2.01%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Wasatch-1st Source Income Fund	1 Year	5 Years	10 Years
Investor Class	0.75%	1.70%	3.14%
Investor Class | Return After Taxes on Distributions	0.04%	0.98%	2.12%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	0.43%	1.02%	2.05%
Barclays Capital U.S. Intermediate Government/Credit Bond Index (reflects no deductions for fees, expenses or taxes)	1.07%	2.58%	4.04%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Wasatch-1st Source Income Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH-1ST SOURCE INCOME FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is to seek current income consistent with the preservation of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

44.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund normally invests at least 65% of its total assets in debt securities of all types, including corporate bonds, U.S. government bonds, and variable and floating rate securities.
Consistent with the Wasatch-1st Source Income Fund’s (Income Fund) investment objective, 1st Source Corporation Investment Advisors, Inc. (1st Source), the Fund’s Sub-Advisor, expects the Fund to:

• Invest substantially all, but in no event less than 65%, of the Fund’s total assets at the time of purchase in debt securities.
• Invest in fixed income securities consisting of bonds, fixed income preferred stocks, debentures, notes, zero-coupon securities, mortgage-related and other asset-backed securities, state, municipal or industrial revenue bonds, obligations issued or guaranteed by agencies or instrumentalities of the U.S. government, debt securities convertible into or exchangeable for common stocks, foreign debt securities, income participation loans, guaranteed investment contracts, first mortgage loans and participation certificates in pools of mortgages issued or guaranteed by agencies or instrumentalities of the U.S. government.
• Typically invest in debt securities rated at the time of purchase within the four highest rating categories assigned by one or more nationally recognized statistical rating organizations (NRSROs) or, if unrated, those which 1st Source deems to be of comparable quality. The Fund may also invest up to 10% of its total assets in non-investment grade debt securities.

The Fund may engage in repurchase transactions, credit default swaps, forward contracts, and may also engage in futures transactions solely for hedging purposes, and may invest in options on futures. The Fund may also invest in other investment companies.
The Fund may purchase securities on a when-issued or delayed delivery basis, in which a security’s price and yield are fixed on a specific date, but payment and delivery are scheduled for a future date beyond the standard settlement period.
It is anticipated that the Fund will have an average maturity of 3-1/2 years to 5 years and an effective duration of 2-1/2 years to 4-1/2 years.
The Fund may invest a large percentage of its assets in a few sectors, including financials and heath care.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including financials and heath care.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.
Convertible Securities Risk. The Fund may invest in convertible securities, which are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and have less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security then the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Ratings Agency Risk. Credit quality in the high yield securities market can change suddenly and unexpectedly, and even recently issued credit ratings may not fully reflect the actual risks posed by a particular high yield security. For these reasons, it is generally the policy of 1st Source not to rely exclusively on ratings issued by established NRSROs, but to supplement such ratings with its own independent and ongoing review of credit quality. The achievement of the Fund’s investment objective by investments in such securities may be more dependent on 1st Source’s credit analysis than is the case for higher quality bonds. Should the rating of a portfolio security be downgraded, 1st Source will determine whether it is in the best interests of the Fund to retain or dispose of such security.
Repurchase Agreements Risk. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
When-Issued Securities Risk. The Fund may purchase securities on a “when-issued” basis (i.e., for delivery beyond the normal settlement date at a stated price and yield). When the Fund engages in “when-issued” transactions, it relies on the seller to consummate the trade. Failure of the seller to do so may result in the Fund incurring a loss or missing the opportunity to obtain a price considered to be advantageous. The Fund will engage in “when-issued” delivery transactions only for the purpose of acquiring portfolio securities consistent with the Fund’s investment objective and strategies and not for investment leverage.
Investment Companies Risk. The Fund may invest in the shares of other investment companies, including foreign and domestic registered and unregistered open-end funds, closed-end funds, unit investment trusts and exchange-traded funds. Investing in another investment company subjects the Fund to the same risks associated with investing in the securities held by the applicable investment company and the investment strategies employed by such funds (such as the use of leverage). In addition, the benefit of investing in another investment company is largely dependent on the skill of the investment advisor of the underlying company and whether the associated fees and costs involved with investing in such company are offset by the potential gains. As a shareholder in an investment company, the Fund will bear its ratable share of that investment company’s expenses including advisory and administrative fees. Fund shareholders would therefore be subject to duplicative expenses to the extent that the Fund invests in other investment companies.
Derivatives Risk. The Fund may suffer a loss from its use of put and call options and futures contracts, which are forms of derivatives. Derivatives can amplify a gain or loss, potentially earning or losing substantially more money than the actual cost of the derivative instrument, with the potential for unlimited losses on certain instruments. Derivatives may be difficult to value, may become illiquid, and may affect the timing and character of taxes payable by shareholders.
Credit Default Swaps Risk. The Fund may enter into credit default swaps, interest rate swaps and currency swaps. Swap agreements will tend to shift a fund’s investment exposure from one type of investment to another. Depending on how they are used, swap agreements may increase or decrease the overall volatility of the Fund’s portfolio and its share price and yield. Swaps are subject to counterparty risk. The Fund bears the loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. For this reason, the Fund will enter into swap agreements only with counterparties that meet certain standards of creditworthiness.
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund commenced operations on December 15, 2008 upon the reorganization of the 1st Source Monogram Income Fund, the Fund’s predecessor fund (the “Predecessor Fund”), into the Fund. With the reorganization, the Fund assumed the financial and performance history of the Predecessor Fund. The following tables provide information on how the Investor Class of the Fund (and Predecessor Fund for periods prior to December 15, 2008) has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based bond market index. In addition, the Predecessor Fund was advised by a different investment advisor and subject to different expenses, which may have produced different investment results. The portfolio manager of the Fund, however, was also the portfolio manager of the Predecessor Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total returns table allows you to compare the Fund’s (and Predecessor Fund’s for periods prior to December 15, 2008) performance over the time periods indicated to that of a broad-based bond market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH-1ST SOURCE INCOME FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 9/30/2006	2.85%
Worst — 6/30/2013	-2.01%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch-1st Source Income Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.55%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.17%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.73%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 75

3 Years

rr_ExpenseExampleYear03

234

5 Years

rr_ExpenseExampleYear05

407

10 Years

rr_ExpenseExampleYear10

$ 908

2006

rr_AnnualReturn2006

3.72%

2007

rr_AnnualReturn2007

5.61%

2008

rr_AnnualReturn2008

3.54%

2009

rr_AnnualReturn2009

5.98%

2010

rr_AnnualReturn2010

4.22%

2011

rr_AnnualReturn2011

3.86%

2012

rr_AnnualReturn2012

2.81%

2013

rr_AnnualReturn2013

(1.49%)

2014

rr_AnnualReturn2014

2.66%

2015

rr_AnnualReturn2015

0.75%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2006

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

2.85%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2013

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(2.01%)

1 Year

rr_AverageAnnualReturnYear01

0.75%

5 Years

rr_AverageAnnualReturnYear05

1.70%

10 Years

rr_AverageAnnualReturnYear10

3.14%

Wasatch-1st Source Income Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.04%

5 Years

rr_AverageAnnualReturnYear05

0.98%

10 Years

rr_AverageAnnualReturnYear10

2.12%

Wasatch-1st Source Income Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.43%

5 Years

rr_AverageAnnualReturnYear05

1.02%

10 Years

rr_AverageAnnualReturnYear10

2.05%

Wasatch-1st Source Income Fund | Barclays Capital U.S. Intermediate Government/Credit Bond Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.07%

5 Years

rr_AverageAnnualReturnYear05

2.58%

10 Years

rr_AverageAnnualReturnYear10

4.04%

[1] The Total Annual Fund Operating Expenses may not equal the expense ratio stated in the Fund's most recent Annual Report and Financial Highlights, which reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

XML

Wasatch-Hoisington U.S. Treasury Fund

WASATCH-HOISINGTON U.S. TREASURY FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is to provide a rate of return that exceeds the rate of inflation over a business cycle by investing in U.S. Treasury securities with an emphasis on both income and capital appreciation.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Wasatch-Hoisington U.S. Treasury Fund Investor Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Wasatch-Hoisington U.S. Treasury Fund Investor Class Shares
Management Fee	0.50%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.17%
Total Annual Fund Operating Expenses	0.67%	[1]

EXAMPLE

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Wasatch-Hoisington U.S. Treasury Fund | Investor Class | USD ($)	68	214	373	834

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 131% of the average value of its portfolio.

PRINCIPAL STRATEGIES

In pursuit of the Fund’s investment objective, Hoisington Investment Management Company (HIMCO), the Fund’s Sub-Advisor, will:

• Typically invest at least 90% of the Fund’s total assets in U.S. Treasury securities and in repurchase agreements collateralized by such securities.
• Adjust the average maturity and effective duration of the Fund’s portfolio based on HIMCO’s assessment of multi-year trends in national and international economic conditions.
• Invest in long-term U.S. Treasury bonds, including U.S. Treasury Strips (zero coupon Treasury securities), when HIMCO determines that economic conditions suggest lower inflation and the multi-year trend is toward decreasing interest rates.
• Invest in U.S. Treasury bills or notes, TIPS, and FRNs (maturities less than five years) when HIMCO determines that economic conditions suggest rising inflation and the multi-year trend is toward increasing interest rates.

Over the course of a business cycle, under normal market conditions:

• The effective duration of the Fund’s holdings is expected to vary from less than a year to a maximum of 25 years.
• The Fund’s holdings will range in maturity from less than a year to a maximum of the longest maturity Treasury bonds available. As of September 30, 2015, the effective duration of the Fund’s holdings was 20.42 years, and the average maturity of the Fund’s holdings was 28.51 years.
• When the Fund is invested in securities with longer weighted average maturities it will be more sensitive to changes in market interest rates and its share price may be subject to greater volatility.
• The Fund’s portfolio turnover rate will vary substantially from year to year. During some periods, turnover will be well below 50%. At other times, turnover could exceed 200% annually. At these times, increased portfolio turnover may result in higher transaction costs and may also result in taxable capital gains.
• Portfolio adjustments may require the sale of securities prior to their maturity date. The goal of these transactions will be to increase income and/or change the duration of the overall portfolio.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. HIMCO seeks to limit credit risk by investing in U.S. Treasury securities backed by the full faith and credit of the U.S. government which are viewed as carrying minimal credit risk.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to an increase in market interest rates. Even though U.S. Treasury securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Effective Duration. Effective duration is a measure of the responsiveness of a bond’s price to market interest rate changes. For example, if the interest rate increased 1%, a bond with an effective duration of five years would experience a decline in price of approximately 5%. Similarly, if the interest rate increased 1%, the price of a bond with an effective duration of 15 years would decline approximately 15%. The effective duration of the longest maturity U.S. zero coupon bond is 30 years. If the interest rate increased 1%, the value of the longest maturity zero coupon bond would decline approximately 30%. Similarly, if the interest rate decreased 1%, the value of the longest maturity zero coupon bond would increase approximately 30%.
Repurchase Agreements Risk. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
Risks of Zero Coupon Treasury Securities. The market prices of zero coupon securities, which do not entitle the holder to periodic interest payments, are generally more volatile than the market prices of securities of comparable quality and similar maturity that do pay interest periodically. Zero coupon securities are more sensitive to fluctuations in interest rates than coupon securities of the same maturity.
Volatility Risk. Longer-term bonds are more sensitive to interest rate changes than shorter-term notes and bills. Prices of debt securities move inversely to interest rates. As a result, when the Fund is invested in longer-term securities, it may experience significant negative returns when long-term interest rates increase.

HISTORICAL PERFORMANCE

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based bond market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH-HOISINGTON U.S. TREASURY FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 9/30/2011	36.15%
Worst — 12/31/2010	-11.47%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Wasatch-Hoisington U.S. Treasury Fund	1 Year	5 Years	10 Years
Investor Class	(2.84%)	9.27%	7.23%
Investor Class | Return After Taxes on Distributions	(4.83%)	7.69%	5.58%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	(0.70%)	6.90%	5.26%
Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)	0.55%	3.25%	4.51%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Wasatch-Hoisington U.S. Treasury Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH-HOISINGTON U.S. TREASURY FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is to provide a rate of return that exceeds the rate of inflation over a business cycle by investing in U.S. Treasury securities with an emphasis on both income and capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Investor Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 131% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

131.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Investor Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Investor Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Investor Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

In pursuit of the Fund’s investment objective, Hoisington Investment Management Company (HIMCO), the Fund’s Sub-Advisor, will:

• Typically invest at least 90% of the Fund’s total assets in U.S. Treasury securities and in repurchase agreements collateralized by such securities.
• Adjust the average maturity and effective duration of the Fund’s portfolio based on HIMCO’s assessment of multi-year trends in national and international economic conditions.
• Invest in long-term U.S. Treasury bonds, including U.S. Treasury Strips (zero coupon Treasury securities), when HIMCO determines that economic conditions suggest lower inflation and the multi-year trend is toward decreasing interest rates.
• Invest in U.S. Treasury bills or notes, TIPS, and FRNs (maturities less than five years) when HIMCO determines that economic conditions suggest rising inflation and the multi-year trend is toward increasing interest rates.

Over the course of a business cycle, under normal market conditions:

• The effective duration of the Fund’s holdings is expected to vary from less than a year to a maximum of 25 years.
• The Fund’s holdings will range in maturity from less than a year to a maximum of the longest maturity Treasury bonds available. As of September 30, 2015, the effective duration of the Fund’s holdings was 20.42 years, and the average maturity of the Fund’s holdings was 28.51 years.
• When the Fund is invested in securities with longer weighted average maturities it will be more sensitive to changes in market interest rates and its share price may be subject to greater volatility.
• The Fund’s portfolio turnover rate will vary substantially from year to year. During some periods, turnover will be well below 50%. At other times, turnover could exceed 200% annually. At these times, increased portfolio turnover may result in higher transaction costs and may also result in taxable capital gains.
• Portfolio adjustments may require the sale of securities prior to their maturity date. The goal of these transactions will be to increase income and/or change the duration of the overall portfolio.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. HIMCO seeks to limit credit risk by investing in U.S. Treasury securities backed by the full faith and credit of the U.S. government which are viewed as carrying minimal credit risk.
Interest Rate Risk. Interest rate risk is the risk that a debt security’s value will decline due to an increase in market interest rates. Even though U.S. Treasury securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Income Risk. Income risk is the potential for a decline in the Fund’s income due to falling interest rates.
Effective Duration. Effective duration is a measure of the responsiveness of a bond’s price to market interest rate changes. For example, if the interest rate increased 1%, a bond with an effective duration of five years would experience a decline in price of approximately 5%. Similarly, if the interest rate increased 1%, the price of a bond with an effective duration of 15 years would decline approximately 15%. The effective duration of the longest maturity U.S. zero coupon bond is 30 years. If the interest rate increased 1%, the value of the longest maturity zero coupon bond would decline approximately 30%. Similarly, if the interest rate decreased 1%, the value of the longest maturity zero coupon bond would increase approximately 30%.
Repurchase Agreements Risk. The main risk of a repurchase agreement is that the original seller might default on its obligation to repurchase the securities. If the seller defaults, the Fund will seek to recover its investment by selling the collateral and could encounter restrictions, costs or delays. The Fund will suffer a loss if it sells the collateral for less than the repurchase price.
Risks of Zero Coupon Treasury Securities. The market prices of zero coupon securities, which do not entitle the holder to periodic interest payments, are generally more volatile than the market prices of securities of comparable quality and similar maturity that do pay interest periodically. Zero coupon securities are more sensitive to fluctuations in interest rates than coupon securities of the same maturity.
Volatility Risk. Longer-term bonds are more sensitive to interest rate changes than shorter-term notes and bills. Prices of debt securities move inversely to interest rates. As a result, when the Fund is invested in longer-term securities, it may experience significant negative returns when long-term interest rates increase.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Investor Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Investor Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based bond market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based bond market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Investor Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH-HOISINGTON U.S. TREASURY FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 9/30/2011	36.15%
Worst — 12/31/2010	-11.47%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Wasatch-Hoisington U.S. Treasury Fund | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.17%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.67%

^[1]

1 Year

rr_ExpenseExampleYear01

$ 68

3 Years

rr_ExpenseExampleYear03

214

5 Years

rr_ExpenseExampleYear05

373

10 Years

rr_ExpenseExampleYear10

$ 834

2006

rr_AnnualReturn2006

(0.18%)

2007

rr_AnnualReturn2007

10.00%

2008

rr_AnnualReturn2008

37.77%

2009

rr_AnnualReturn2009

(22.56%)

2010

rr_AnnualReturn2010

10.18%

2011

rr_AnnualReturn2011

41.23%

2012

rr_AnnualReturn2012

2.78%

2013

rr_AnnualReturn2013

(16.71%)

2014

rr_AnnualReturn2014

32.58%

2015

rr_AnnualReturn2015

(2.48%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2011

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

36.15%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2010

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(11.47%)

1 Year

rr_AverageAnnualReturnYear01

(2.84%)

5 Years

rr_AverageAnnualReturnYear05

9.27%

10 Years

rr_AverageAnnualReturnYear10

7.23%

Wasatch-Hoisington U.S. Treasury Fund | Return After Taxes on Distributions | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.83%)

5 Years

rr_AverageAnnualReturnYear05

7.69%

10 Years

rr_AverageAnnualReturnYear10

5.58%

Wasatch-Hoisington U.S. Treasury Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(0.70%)

5 Years

rr_AverageAnnualReturnYear05

6.90%

10 Years

rr_AverageAnnualReturnYear10

5.26%

Wasatch-Hoisington U.S. Treasury Fund | Barclays Capital U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.55%

5 Years

rr_AverageAnnualReturnYear05

3.25%

10 Years

rr_AverageAnnualReturnYear10

4.51%

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Investor Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.75% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch Core Growth Fund

WASATCH CORE GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Core Growth Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Core Growth Fund Institutional Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.13%
Total Annual Fund Operating Expenses	1.13%
Expense Reimbursement	(0.08%)	[1]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.05%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Core Growth Fund | Institutional Class | USD ($)	107	351	614	1,366

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The companies in which we invest are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We focus on companies that we consider to be high quality. We use a process of “bottom-up” fundamental analysis to look for individual companies that we believe are stable and have the potential to grow steadily for long periods of time. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

HISTORICAL PERFORMANCE

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH CORE GROWTH FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 12/31/2014	9.87%
Worst — 9/30/2015	-8.14%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Core Growth Fund	1 Year	Since Inception	Inception Date
Institutional Class	3.98%	13.08%	Jan. 31, 2012
Institutional Class | Return After Taxes on Distributions	1.24%	12.05%	Jan. 31, 2012
Institutional Class | Return After Taxes on Distributions and Sale of Fund Shares	4.57%	10.36%	Jan. 31, 2012
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	(4.41%)	11.16%	Jan. 31, 2012
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	(1.38%)	12.60%	Jan. 31, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Core Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH CORE GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in smaller growing companies at reasonable prices.
Under normal market conditions, we will invest at least 65% of the Fund’s net assets in the equity securities of growing companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The companies in which we invest are usually small to mid-size with market capitalizations of less than $5 billion at the time of purchase.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
We focus on companies that we consider to be high quality. We use a process of “bottom-up” fundamental analysis to look for individual companies that we believe are stable and have the potential to grow steadily for long periods of time. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund seeks to purchase stocks at prices we believe are reasonable relative to our projection of a company’s long term earnings growth rate. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH CORE GROWTH FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 12/31/2014	9.87%
Worst — 9/30/2015	-8.14%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Core Growth Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.13%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.08%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.05%

1 Year

rr_ExpenseExampleYear01

$ 107

3 Years

rr_ExpenseExampleYear03

351

5 Years

rr_ExpenseExampleYear05

614

10 Years

rr_ExpenseExampleYear10

$ 1,366

2013

rr_AnnualReturn2013

30.27%

2014

rr_AnnualReturn2014

6.18%

2015

rr_AnnualReturn2015

3.98%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2014

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

9.87%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(8.14%)

1 Year

rr_AverageAnnualReturnYear01

3.98%

Since Inception

rr_AverageAnnualReturnSinceInception

13.08%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Core Growth Fund | Return After Taxes on Distributions | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.24%

Since Inception

rr_AverageAnnualReturnSinceInception

12.05%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Core Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.57%

Since Inception

rr_AverageAnnualReturnSinceInception

10.36%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Core Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.41%)

Since Inception

rr_AverageAnnualReturnSinceInception

11.16%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Core Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.38%)

Since Inception

rr_AverageAnnualReturnSinceInception

12.60%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch Emerging India Fund

WASATCH EMERGING INDIA FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Emerging India Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Emerging India Fund Institutional Class Shares
Management Fee	1.25%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.50%	[2]
Total Annual Fund Operating Expenses	1.75%
Expense Reimbursement	(0.25%)	[3]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.50%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Emerging India Fund | Institutional Class | USD ($)	153	527	926	2,042

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 36% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies tied economically to India.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies tied economically to India. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
We will generally consider qualifying investments to be in companies that are listed on an Indian exchange, that have at least 50% of their assets in India, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in India.
The Fund is expected to invest across market capitalization levels, ranging from small capitalization stocks to larger capitalization stocks. However, we expect the Fund to invest a significant portion of its assets in small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We use a process of quantitative screening followed by “bottom up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.
We may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Indian Market Risk. Government actions, bureaucratic obstacles and inconsistent economic and tax reform within the Indian government have had a significant effect on the economy and could adversely affect market conditions, deter economic growth and reduce the profitability of private enterprises. Global factors and foreign actions may inhibit the flow of foreign capital on which India is dependent to sustain its growth. Large portions of many Indian companies remain in the hands of their founders (including members of their families). Family-controlled companies may have weaker and less transparent corporate governance, which increases the potential for loss and unequal treatment of investors. India experiences many of the market risks associated with developing economies, including relatively low levels of liquidity, which may result in extreme volatility in the prices of Indian securities. Religious, cultural and military disputes persist in India, and between India and Pakistan (as well as sectarian groups within each country). The threat of aggression in the region could hinder development of the Indian economy, and escalating tensions could impact the broader region, including China.
Because the Fund concentrates its investments in a single region of the world, the value of the Fund’s shares may be affected by events that adversely affect India and may fluctuate more than the value of a less concentrated fund’s shares.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING INDIA FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2012	21.43%
Worst — 6/30/2012	-6.95%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Emerging India Fund		1 Year	Since Inception	Inception Date
Investor Class		4.16%	9.83%	Apr. 26, 2011
Investor Class | Return After Taxes on Distributions		3.81%	9.71%	Apr. 26, 2011
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		2.63%	7.77%	Apr. 26, 2011
MSCI India Investable Market Index (reflects no deductions for fees, expenses or taxes)	[1]	(4.69%)	(1.23%)	Apr. 26, 2011

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Emerging India Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING INDIA FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 36% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

36.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in companies tied economically to India.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies tied economically to India. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
We will generally consider qualifying investments to be in companies that are listed on an Indian exchange, that have at least 50% of their assets in India, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in India.
The Fund is expected to invest across market capitalization levels, ranging from small capitalization stocks to larger capitalization stocks. However, we expect the Fund to invest a significant portion of its assets in small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We use a process of quantitative screening followed by “bottom up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.
We may also invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Indian Market Risk. Government actions, bureaucratic obstacles and inconsistent economic and tax reform within the Indian government have had a significant effect on the economy and could adversely affect market conditions, deter economic growth and reduce the profitability of private enterprises. Global factors and foreign actions may inhibit the flow of foreign capital on which India is dependent to sustain its growth. Large portions of many Indian companies remain in the hands of their founders (including members of their families). Family-controlled companies may have weaker and less transparent corporate governance, which increases the potential for loss and unequal treatment of investors. India experiences many of the market risks associated with developing economies, including relatively low levels of liquidity, which may result in extreme volatility in the prices of Indian securities. Religious, cultural and military disputes persist in India, and between India and Pakistan (as well as sectarian groups within each country). The threat of aggression in the region could hinder development of the Indian economy, and escalating tensions could impact the broader region, including China.
Because the Fund concentrates its investments in a single region of the world, the value of the Fund’s shares may be affected by events that adversely affect India and may fluctuate more than the value of a less concentrated fund’s shares.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index composed of securities similar to those held by the Fund.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH EMERGING INDIA FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/2012	21.43%
Worst — 6/30/2012	-6.95%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Institutional Class | Wasatch Emerging India Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.50%

^[2]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.75%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.25%)

^[3]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.50%

1 Year

rr_ExpenseExampleYear01

$ 153

3 Years

rr_ExpenseExampleYear03

527

5 Years

rr_ExpenseExampleYear05

926

10 Years

rr_ExpenseExampleYear10

$ 2,042

Institutional Class | Wasatch Emerging India Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2012

rr_AnnualReturn2012

33.77%

2013

rr_AnnualReturn2013

(1.46%)

2014

rr_AnnualReturn2014

45.40%

2015

rr_AnnualReturn2015

4.16%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2012

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

21.43%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2012

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(6.95%)

1 Year

rr_AverageAnnualReturnYear01

4.16%

Since Inception

rr_AverageAnnualReturnSinceInception

9.83%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Institutional Class | Wasatch Emerging India Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.81%

Since Inception

rr_AverageAnnualReturnSinceInception

9.71%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Institutional Class | Wasatch Emerging India Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.63%

Since Inception

rr_AverageAnnualReturnSinceInception

7.77%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

Institutional Class | Wasatch Emerging India Fund | MSCI India Investable Market Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.69%)

^[4]

Since Inception

rr_AverageAnnualReturnSinceInception

(1.23%)

^[4]

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 26, 2011

^[4]

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.50% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[4] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Institutional Class | Wasatch Emerging Markets Select Fund

WASATCH EMERGING MARKETS SELECT FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Emerging Markets Select Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Emerging Markets Select Fund Institutional Class Shares
Management Fee	1.00%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.51%
Interest Expense	0.01%
Total Annual Fund Operating Expenses	1.52%
Expense Reimbursement	(0.31%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.21%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Emerging Markets Select Fund | Institutional Class | USD ($)	123	450	800	1,786

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, materials, telecommunication services, and in convertible securities.
The Fund may invest in initial public offerings (IPOs) and early stage companies.
Under normal market conditions, the Fund will generally invest in 30 to 50 companies. However, we may invest in fewer or more companies when we believe that doing so will help our efforts to achieve the Fund’s investment objective.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Convertible Securities Risk. The Fund may invest in convertible securities, which are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and have less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security then the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

HISTORICAL PERFORMANCE

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING MARKETS SELECT FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2014	4.34%
Worst — 9/30/2015	-15.05%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Emerging Markets Select Fund		1 Year	Since Inception	Inception Date
Institutional Class		(16.96%)	(4.90%)	Dec. 31, 2012
Institutional Class | Return After Taxes on Distributions		(16.96%)	(4.88%)	Dec. 31, 2012
Institutional Class | Return After Taxes on Distributions and Sale of Fund Shares		(9.60%)	(3.60%)	Dec. 31, 2012
MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(14.92%)	(6.22%)	Dec. 31, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Effective January 31, 2016, the management fee was reduced from 1.25% to 1.00%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.20% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Emerging Markets Select Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING MARKETS SELECT FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

46.00%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in companies of all market capitalizations that are tied economically to emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to emerging market countries. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, materials, telecommunication services, and in convertible securities.
The Fund may invest in initial public offerings (IPOs) and early stage companies.
Under normal market conditions, the Fund will generally invest in 30 to 50 companies. However, we may invest in fewer or more companies when we believe that doing so will help our efforts to achieve the Fund’s investment objective.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, materials, telecommunication services, and in convertible securities.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Convertible Securities Risk. The Fund may invest in convertible securities, which are preferred stocks or debt obligations that are convertible into common stock. Generally, convertible securities offer lower interest or dividend yields than non-convertible securities of similar quality, and have less potential for gains or capital appreciation in a rising stock market than other equity securities. They tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than the markets for common stocks or bonds. Convertible securities have both equity and fixed income risk characteristics. Like all fixed income securities, the value of convertible securities is susceptible to the risk of market losses attributable to changes in interest rates. The market value of convertible securities tends to decline as interest rates increase. If, however, the market price of the common stock underlying a convertible security approaches or exceeds the conversion price of the convertible security then the convertible security tends to reflect the market price of the underlying common stock. In such a case, a convertible security may lose much or all of its value if the value of the underlying common stock then falls below the conversion price of the security. As the market price of the underlying common stock declines, the convertible security tends to trade increasingly based on its fixed income characteristics, and thus, may not necessarily decline in price as much as the underlying common stock. Additionally, an issuer may have the right to buy back a convertible security at a time and price that is unfavorable to the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH EMERGING MARKETS SELECT FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2014	4.34%
Worst — 9/30/2015	-15.05%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Emerging Markets Select Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Interest Expense

rr_Component2OtherExpensesOverAssets

0.01%

Other Expenses

rr_OtherExpensesOverAssets

0.51%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.52%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.31%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.21%

1 Year

rr_ExpenseExampleYear01

$ 123

3 Years

rr_ExpenseExampleYear03

450

5 Years

rr_ExpenseExampleYear05

800

10 Years

rr_ExpenseExampleYear10

$ 1,786

2013

rr_AnnualReturn2013

(2.64%)

2014

rr_AnnualReturn2014

4.24%

2015

rr_AnnualReturn2015

(16.96%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2014

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

4.34%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.05%)

1 Year

rr_AverageAnnualReturnYear01

(16.96%)

Since Inception

rr_AverageAnnualReturnSinceInception

(4.90%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 2012

Institutional Class | Wasatch Emerging Markets Select Fund | Return After Taxes on Distributions | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(16.96%)

Since Inception

rr_AverageAnnualReturnSinceInception

(4.88%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 2012

Institutional Class | Wasatch Emerging Markets Select Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(9.60%)

Since Inception

rr_AverageAnnualReturnSinceInception

(3.60%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 2012

Institutional Class | Wasatch Emerging Markets Select Fund | MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.92%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

(6.22%)

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 2012

^[3]

[1] Effective January 31, 2016, the management fee was reduced from 1.25% to 1.00%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.20% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Institutional Class | Wasatch Emerging Markets Small Cap Fund

WASATCH EMERGING MARKETS SMALL CAP FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Emerging Markets Small Cap Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Emerging Markets Small Cap Fund Institutional Class Shares
Management Fee	1.65%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.17%	[2]
Total Annual Fund Operating Expenses	1.82%
Expense Reimbursement	(0.02%)	[3]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.80%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Emerging Markets Small Cap Fund | Institutional Class | USD ($)	183	571	984	2,136

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 59% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small companies tied economically to emerging markets.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of US$3 billion or the market capitalization of the largest company in the Morgan Stanley Capital International (MSCI) Emerging Markets Small Cap Index during the most recent 12-month period. As of its most recent reconstitution date, the market capitalization of the largest company in the MSCI Emerging Markets Small Cap Index was $6.4 billion. The capitalization of the largest company in the MSCI Emerging Markets Small Cap Index is subject to change at its next reconstitution date.
Emerging market countries are those currently included in the MSCI Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH EMERGING MARKETS SMALL CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	56.10%
Worst — 12/31/2008	-32.16%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Emerging Markets Small Cap Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Class		(9.35%)	(0.64%)	2.79%	Oct. 01, 2007
Investor Class | Return After Taxes on Distributions		(9.35%)	(0.71%)	2.71%	Oct. 01, 2007
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		(5.29%)	(0.41%)	2.21%	Oct. 01, 2007
MSCI Emerging Markets Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	(6.85%)	(3.29%)	(0.64%)	Oct. 01, 2007
MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(14.92%)	(4.81%)	(2.63%)	Oct. 01, 2007

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Effective January 31, 2016, the management fee was reduced from 1.75% to 1.65%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.80% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Emerging Markets Small Cap Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH EMERGING MARKETS SMALL CAP FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 59% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

59.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small companies tied economically to emerging markets.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies that are tied economically to emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of US$3 billion or the market capitalization of the largest company in the Morgan Stanley Capital International (MSCI) Emerging Markets Small Cap Index during the most recent 12-month period. As of its most recent reconstitution date, the market capitalization of the largest company in the MSCI Emerging Markets Small Cap Index was $6.4 billion. The capitalization of the largest company in the MSCI Emerging Markets Small Cap Index is subject to change at its next reconstitution date.
Emerging market countries are those currently included in the MSCI Emerging Markets Index. We will generally consider qualifying investments to be in companies that are listed on an exchange in an emerging market country, that have at least 50% of their assets in an emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services performed in an emerging market country.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

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HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

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The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH EMERGING MARKETS SMALL CAP FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns

Best — 6/30/2009	56.10%
Worst — 12/31/2008	-32.16%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

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Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

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The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

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The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Emerging Markets Small Cap Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.65%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.17%

^[2]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.82%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.02%)

^[3]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.80%

1 Year

rr_ExpenseExampleYear01

$ 183

3 Years

rr_ExpenseExampleYear03

571

5 Years

rr_ExpenseExampleYear05

984

10 Years

rr_ExpenseExampleYear10

$ 2,136

Institutional Class | Wasatch Emerging Markets Small Cap Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2008

rr_AnnualReturn2008

(57.08%)

2009

rr_AnnualReturn2009

117.72%

2010

rr_AnnualReturn2010

41.22%

2011

rr_AnnualReturn2011

(14.01%)

2012

rr_AnnualReturn2012

27.75%

2013

rr_AnnualReturn2013

(3.60%)

2014

rr_AnnualReturn2014

0.89%

2015

rr_AnnualReturn2015

(9.35%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

56.10%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(32.16%)

1 Year

rr_AverageAnnualReturnYear01

(9.35%)

5 Years

rr_AverageAnnualReturnYear05

(0.64%)

Since Inception

rr_AverageAnnualReturnSinceInception

2.79%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Institutional Class | Wasatch Emerging Markets Small Cap Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(9.35%)

5 Years

rr_AverageAnnualReturnYear05

(0.71%)

Since Inception

rr_AverageAnnualReturnSinceInception

2.71%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Institutional Class | Wasatch Emerging Markets Small Cap Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.29%)

5 Years

rr_AverageAnnualReturnYear05

(0.41%)

Since Inception

rr_AverageAnnualReturnSinceInception

2.21%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

Institutional Class | Wasatch Emerging Markets Small Cap Fund | MSCI Emerging Markets Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(6.85%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

(3.29%)

^[4]

Since Inception

rr_AverageAnnualReturnSinceInception

(0.64%)

^[4]

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

^[4]

Institutional Class | Wasatch Emerging Markets Small Cap Fund | MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.92%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

(4.81%)

^[4]

Since Inception

rr_AverageAnnualReturnSinceInception

(2.63%)

^[4]

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 01, 2007

^[4]

[1] Effective January 31, 2016, the management fee was reduced from 1.75% to 1.65%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.80% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[4] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Institutional Class | Wasatch Frontier Emerging Small Countries Fund

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Frontier Emerging Small Countries Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Frontier Emerging Small Countries Fund Institutional Class Shares
Management Fee	1.75%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.34%	[1]
Total Annual Fund Operating Expenses	2.09%
Expense Reimbursement	(0.04%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	2.05%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Frontier Emerging Small Countries Fund | Institutional Class | USD ($)	208	651	1,120	2,418

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 34% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in the equity securities of companies of all market capitalizations that are tied economically to frontier markets and small emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to frontier markets and small emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
“Frontier markets” include any country that is outside the Morgan Stanley Capital International (MSCI) All Country World Index, and also any country that is currently included in the Russell Frontier Index, the S&P Frontier Broad Market Index (BMI), the MSCI Frontier Markets Index, or similar market indices, or any country that, in our opinion, has similar characteristics regardless of its inclusion in an index.
“Emerging markets” include those countries currently considered to be developing as per their inclusion in the MSCI Emerging Markets Index. We consider a “small emerging market country” to be any country that individually constitutes not more than 7% of the MSCI Emerging Markets Index or the S&P Emerging BMI.
We will generally consider qualifying investments to be in companies that are listed on an exchange in a frontier market or small emerging market country, that are legally domiciled in a frontier market or small emerging market country, that have at least 50% of their assets in a frontier market or small emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services provided in a frontier market or small emerging market country. The Fund will not be required to sell a security because the market to which it is economically tied is no longer what we consider to be a frontier market or a small emerging market country.
In general, frontier markets and small emerging market countries, with the exception of the oil-producing Persian Gulf States, tend to have relatively low gross national product per capita compared to the larger traditionally-recognized emerging markets and the world’s major developed economies. Frontier and small emerging market countries include the least developed markets even by emerging market standards. We believe frontier markets and small emerging market countries offer investment opportunities that arise from long-term trends in demographics, deregulation, offshore outsourcing and improving corporate governance.
The Fund may invest in the equity securities of companies of any size, although we expect a significant portion of the Fund’s assets to be invested in companies with market capitalizations of under US$3 billion at the time of purchase.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to frontier markets and small emerging market countries.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, materials and telecommunication services.
We may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries, and in particular small emerging market countries, include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Frontier Markets Risk. In addition to the risks of investing in foreign securities and emerging markets, frontier market securities involve unique risks, such as exposure to economies less diverse and mature than those of the U.S. or more established foreign markets. Economic or political instability may cause larger price changes in frontier market securities than in securities of issuers based in more developed foreign countries, including securities of issuers in larger emerging markets. Frontier markets generally receive less investor attention than developed markets or larger emerging markets. These risks can result in the potential for extreme price volatility and illiquidity.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Liquidity Risk. The trading market for a particular security or type of security in which the Fund invests may be significantly less liquid than domestic or even emerging markets, and there may be little or no trading volume for a period of time for a particular security. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities quickly at the currently marked price when necessary to meet the Fund’s liquidity needs or in response to a specific economic event. It may be difficult at times to sell such securities at any price, which could impact not only the daily Fund NAV, but also the composition of the portfolio if other securities must be sold to meet the Fund’s liquidity needs. Additionally, market quotations for such securities may be volatile affecting the daily NAV of the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2013	8.33%
Worst — 9/30/2015	-7.05%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Frontier Emerging Small Countries Fund		1 Year	Since Inception	Inception Date
Investor Class		(12.10%)	8.84%	Jan. 31, 2012
Investor Class | Return After Taxes on Distributions		(11.92%)	8.84%	Jan. 31, 2012
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		(6.60%)	7.11%	Jan. 31, 2012
MSCI Frontier Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(18.30%)	1.35%	Jan. 31, 2012
MSCI Frontier Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(14.46%)	5.87%	Jan. 31, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Frontier Emerging Small Countries Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 34% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

34.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in the equity securities of companies of all market capitalizations that are tied economically to frontier markets and small emerging market countries.
Under normal market conditions, we will invest at least 80% of the Fund’s assets (plus borrowings for investment purposes) in the equity securities of companies that are tied economically to frontier markets and small emerging market countries. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
“Frontier markets” include any country that is outside the Morgan Stanley Capital International (MSCI) All Country World Index, and also any country that is currently included in the Russell Frontier Index, the S&P Frontier Broad Market Index (BMI), the MSCI Frontier Markets Index, or similar market indices, or any country that, in our opinion, has similar characteristics regardless of its inclusion in an index.
“Emerging markets” include those countries currently considered to be developing as per their inclusion in the MSCI Emerging Markets Index. We consider a “small emerging market country” to be any country that individually constitutes not more than 7% of the MSCI Emerging Markets Index or the S&P Emerging BMI.
We will generally consider qualifying investments to be in companies that are listed on an exchange in a frontier market or small emerging market country, that are legally domiciled in a frontier market or small emerging market country, that have at least 50% of their assets in a frontier market or small emerging market country, or that derive at least 50% of their revenues or profits from goods produced or sold, investments made, or services provided in a frontier market or small emerging market country. The Fund will not be required to sell a security because the market to which it is economically tied is no longer what we consider to be a frontier market or a small emerging market country.
In general, frontier markets and small emerging market countries, with the exception of the oil-producing Persian Gulf States, tend to have relatively low gross national product per capita compared to the larger traditionally-recognized emerging markets and the world’s major developed economies. Frontier and small emerging market countries include the least developed markets even by emerging market standards. We believe frontier markets and small emerging market countries offer investment opportunities that arise from long-term trends in demographics, deregulation, offshore outsourcing and improving corporate governance.
The Fund may invest in the equity securities of companies of any size, although we expect a significant portion of the Fund’s assets to be invested in companies with market capitalizations of under US$3 billion at the time of purchase.
We travel extensively outside the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis with the goal of owning the highest quality growth companies tied economically to frontier markets and small emerging market countries.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, materials and telecommunication services.
We may also invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, materials and telecommunication services.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries, and in particular small emerging market countries, include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Frontier Markets Risk. In addition to the risks of investing in foreign securities and emerging markets, frontier market securities involve unique risks, such as exposure to economies less diverse and mature than those of the U.S. or more established foreign markets. Economic or political instability may cause larger price changes in frontier market securities than in securities of issuers based in more developed foreign countries, including securities of issuers in larger emerging markets. Frontier markets generally receive less investor attention than developed markets or larger emerging markets. These risks can result in the potential for extreme price volatility and illiquidity.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Liquidity Risk. The trading market for a particular security or type of security in which the Fund invests may be significantly less liquid than domestic or even emerging markets, and there may be little or no trading volume for a period of time for a particular security. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities quickly at the currently marked price when necessary to meet the Fund’s liquidity needs or in response to a specific economic event. It may be difficult at times to sell such securities at any price, which could impact not only the daily Fund NAV, but also the composition of the portfolio if other securities must be sold to meet the Fund’s liquidity needs. Additionally, market quotations for such securities may be volatile affecting the daily NAV of the Fund.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Telecommunication Services Sector Risk. The telecommunication services sector is characterized by increasing competition and government regulation. Companies in the telecommunication services sector may encounter distressed cash flows due to the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology. Technological innovations may make the products and services of certain telecommunication companies obsolete.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

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HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

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The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

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WASATCH FRONTIER EMERGING SMALL COUNTRIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns

Best — 3/31/2013	8.33%
Worst — 9/30/2015	-7.05%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

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Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Frontier Emerging Small Countries Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.75%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.34%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.09%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.04%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

2.05%

1 Year

rr_ExpenseExampleYear01

$ 208

3 Years

rr_ExpenseExampleYear03

651

5 Years

rr_ExpenseExampleYear05

1,120

10 Years

rr_ExpenseExampleYear10

$ 2,418

Institutional Class | Wasatch Frontier Emerging Small Countries Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2013

rr_AnnualReturn2013

18.00%

2014

rr_AnnualReturn2014

1.69%

2015

rr_AnnualReturn2015

(12.10%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2013

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

8.33%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(7.05%)

1 Year

rr_AverageAnnualReturnYear01

(12.10%)

Since Inception

rr_AverageAnnualReturnSinceInception

8.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Frontier Emerging Small Countries Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(11.92%)

Since Inception

rr_AverageAnnualReturnSinceInception

8.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Frontier Emerging Small Countries Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(6.60%)

Since Inception

rr_AverageAnnualReturnSinceInception

7.11%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Frontier Emerging Small Countries Fund | MSCI Frontier Emerging Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(18.30%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

1.35%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

^[3]

Institutional Class | Wasatch Frontier Emerging Small Countries Fund | MSCI Frontier Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.46%)

^[3]

Since Inception

rr_AverageAnnualReturnSinceInception

5.87%

^[3]

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

^[3]

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 2.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Institutional Class | Wasatch Global Opportunities Fund

WASATCH GLOBAL OPPORTUNITIES FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Global Opportunities Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Global Opportunities Fund Institutional Class Shares
Management Fee	1.25%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.21%	[2]
Total Annual Fund Operating Expenses	1.46%
Expense Reimbursement	(0.11%)	[3]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.35%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Global Opportunities Fund | Institutional Class | USD ($)	137	450	786	1,735

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 54% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small and micro cap foreign and domestic companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign and domestic companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund may invest a significant portion of its total assets (up to 35% under normal market conditions) in securities of companies with market capitalizations greater than US$5 billion at the time of purchase when the companies meet our investment criteria. The Fund may also invest a significant portion of its total assets in micro cap companies with market capitalizations below US$1 billion (up to 90% under normal market conditions).
The Fund will typically invest in securities issued by companies domiciled in at least three countries, including the United States. The Fund may invest a significant portion of its total assets in companies domiciled in foreign countries (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States). Securities issued by foreign companies incorporated outside the United States whose securities are principally traded in the United States are not defined as “foreign companies” and are not subject to this limitation.
The Fund may invest a significant amount of its total assets (5% to 50% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe are the World’s Best Growth Companies. We travel extensively to visit companies and expect to meet with senior management.
We may also invest in growth companies that we believe have had a temporary setback and therefore have appealing valuation relative to their long-term growth potential.
At times, we may invest in early stage companies with limited or no earnings history if we believe they have outstanding long-term growth potential. We may also invest in initial public offerings (IPOs).
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. We may significantly shift Fund assets between asset classes, sectors, and geographic regions based on where we believe the best growth opportunities and valuations currently exist. The Fund may invest a large percentage of its assets in a few regions or sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Country/Region Risk. Social, political and economic conditions and changes in regulatory, tax, or economic policy in a country or region could significantly affect the market in that country or region. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region might adversely impact the issuers of securities in a different country or region. From time to time, a small number of companies and industries may represent a large portion of the market in a particular country or region, and these companies and industries can be sensitive to adverse social, political, economic, or regulatory developments.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap and Small Company Stock Risk. Micro cap and small company stocks may be very sensitive to changing economic conditions and market downturns because the issuers have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small and micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH GLOBAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	32.73%
Worst — 9/30/2011	-18.94%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Global Opportunities Fund		1 Year	5 Years	Since Inception	Inception Date
Investor Class		3.32%	8.05%	18.48%	Nov. 17, 2008
Investor Class | Return After Taxes on Distributions		0.37%	5.44%	16.24%	Nov. 17, 2008
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		4.26%	6.44%	15.48%	Nov. 17, 2008
MSCI AC World Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	(1.04%)	6.30%	15.44%	Nov. 17, 2008

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.35% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Global Opportunities Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH GLOBAL OPPORTUNITIES FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 54% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

54.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small and micro cap foreign and domestic companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign and domestic companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund may invest a significant portion of its total assets (up to 35% under normal market conditions) in securities of companies with market capitalizations greater than US$5 billion at the time of purchase when the companies meet our investment criteria. The Fund may also invest a significant portion of its total assets in micro cap companies with market capitalizations below US$1 billion (up to 90% under normal market conditions).
The Fund will typically invest in securities issued by companies domiciled in at least three countries, including the United States. The Fund may invest a significant portion of its total assets in companies domiciled in foreign countries (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States). Securities issued by foreign companies incorporated outside the United States whose securities are principally traded in the United States are not defined as “foreign companies” and are not subject to this limitation.
The Fund may invest a significant amount of its total assets (5% to 50% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the Morgan Stanley Capital International (MSCI) EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe are the World’s Best Growth Companies. We travel extensively to visit companies and expect to meet with senior management.
We may also invest in growth companies that we believe have had a temporary setback and therefore have appealing valuation relative to their long-term growth potential.
At times, we may invest in early stage companies with limited or no earnings history if we believe they have outstanding long-term growth potential. We may also invest in initial public offerings (IPOs).
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries. We may significantly shift Fund assets between asset classes, sectors, and geographic regions based on where we believe the best growth opportunities and valuations currently exist. The Fund may invest a large percentage of its assets in a few regions or sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few regions or sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Country/Region Risk. Social, political and economic conditions and changes in regulatory, tax, or economic policy in a country or region could significantly affect the market in that country or region. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibility that conditions in one country or region might adversely impact the issuers of securities in a different country or region. From time to time, a small number of companies and industries may represent a large portion of the market in a particular country or region, and these companies and industries can be sensitive to adverse social, political, economic, or regulatory developments.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap and Small Company Stock Risk. Micro cap and small company stocks may be very sensitive to changing economic conditions and market downturns because the issuers have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small and micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH GLOBAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	32.73%
Worst — 9/30/2011	-18.94%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Global Opportunities Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.21%

^[2]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.46%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.11%)

^[3]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.35%

1 Year

rr_ExpenseExampleYear01

$ 137

3 Years

rr_ExpenseExampleYear03

450

5 Years

rr_ExpenseExampleYear05

786

10 Years

rr_ExpenseExampleYear10

$ 1,735

Institutional Class | Wasatch Global Opportunities Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2009

rr_AnnualReturn2009

61.36%

2010

rr_AnnualReturn2010

26.31%

2011

rr_AnnualReturn2011

(8.87%)

2012

rr_AnnualReturn2012

25.50%

2013

rr_AnnualReturn2013

25.27%

2014

rr_AnnualReturn2014

(0.49%)

2015

rr_AnnualReturn2015

3.32%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

32.73%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(18.94%)

1 Year

rr_AverageAnnualReturnYear01

3.32%

5 Years

rr_AverageAnnualReturnYear05

8.05%

Since Inception

rr_AverageAnnualReturnSinceInception

18.48%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Institutional Class | Wasatch Global Opportunities Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.37%

5 Years

rr_AverageAnnualReturnYear05

5.44%

Since Inception

rr_AverageAnnualReturnSinceInception

16.24%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Institutional Class | Wasatch Global Opportunities Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.26%

5 Years

rr_AverageAnnualReturnYear05

6.44%

Since Inception

rr_AverageAnnualReturnSinceInception

15.48%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

Institutional Class | Wasatch Global Opportunities Fund | MSCI AC World Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.04%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

6.30%

^[4]

Since Inception

rr_AverageAnnualReturnSinceInception

15.44%

^[4]

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 17, 2008

^[4]

[1] Effective January 31, 2016, the management fee was reduced from 1.50% to 1.25%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.35% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[4] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Institutional Class | Wasatch International Growth Fund

WASATCH INTERNATIONAL GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch International Growth Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch International Growth Fund Institutional Class Shares
Management Fee	1.25%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.12%	[1]
Total Annual Fund Operating Expenses	1.37%
Expense Reimbursement	(0.02%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.35%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch International Growth Fund | Institutional Class | USD ($)	137	432	748	1,645

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 46% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in foreign growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (5% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH INTERNATIONAL GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	41.88%
Worst — 9/30/2008	-28.61%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch International Growth Fund	1 Year	5 Years	10 Years
Investor Class	15.21%	9.17%	8.17%
Investor Class | Return After Taxes on Distributions	15.21%	9.00%	7.48%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	8.61%	7.25%	6.60%
MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	2.60%	2.63%	4.97%
MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	5.46%	4.39%	4.09%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

**Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.35% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch International Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH INTERNATIONAL GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 46% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

46.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in foreign growth companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (5% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH INTERNATIONAL GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	41.88%
Worst — 9/30/2008	-28.61%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Footnotes

rr_PerformanceTableFootnotesTextBlock

**Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

Institutional Class | Wasatch International Growth Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.25%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.12%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.37%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.02%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.35%

1 Year

rr_ExpenseExampleYear01

$ 137

3 Years

rr_ExpenseExampleYear03

432

5 Years

rr_ExpenseExampleYear05

748

10 Years

rr_ExpenseExampleYear10

$ 1,645

Institutional Class | Wasatch International Growth Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2006

rr_AnnualReturn2006

23.79%

2007

rr_AnnualReturn2007

12.47%

2008

rr_AnnualReturn2008

(53.93%)

2009

rr_AnnualReturn2009

64.19%

2010

rr_AnnualReturn2010

34.24%

2011

rr_AnnualReturn2011

(12.04%)

2012

rr_AnnualReturn2012

33.08%

2013

rr_AnnualReturn2013

26.42%

2014

rr_AnnualReturn2014

(9.05%)

2015

rr_AnnualReturn2015

15.21%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

41.88%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(28.61%)

1 Year

rr_AverageAnnualReturnYear01

15.21%

5 Years

rr_AverageAnnualReturnYear05

9.17%

10 Years

rr_AverageAnnualReturnYear10

8.17%

Institutional Class | Wasatch International Growth Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.21%

5 Years

rr_AverageAnnualReturnYear05

9.00%

10 Years

rr_AverageAnnualReturnYear10

7.48%

Institutional Class | Wasatch International Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.61%

5 Years

rr_AverageAnnualReturnYear05

7.25%

10 Years

rr_AverageAnnualReturnYear10

6.60%

Institutional Class | Wasatch International Growth Fund | MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.60%

5 Years

rr_AverageAnnualReturnYear05

2.63%

10 Years

rr_AverageAnnualReturnYear10

4.97%

Institutional Class | Wasatch International Growth Fund | MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.46%

5 Years

rr_AverageAnnualReturnYear05

4.39%

10 Years

rr_AverageAnnualReturnYear10

4.09%

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.35% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch International Opportunities Fund

WASATCH INTERNATIONAL OPPORTUNITIES FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch International Opportunities Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch International Opportunities Fund Institutional Class Shares
Management Fee	1.75%	[1]
Distribution/Service (12b-1) Fee	none
Other Expenses	0.21%	[2]
Total Annual Fund Operating Expenses	1.96%
Expense Reimbursement	(0.01%)	[3]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.95%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch International Opportunities Fund | Institutional Class | USD ($)	198	614	1,056	2,284

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 25% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in foreign micro cap companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$1 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (20% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, health care, industrials, information technology and materials.
The Fund may also invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH INTERNATIONAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	44.35%
Worst — 9/30/2008	-27.60%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch International Opportunities Fund		1 Year	5 Years	10 Years
Investor Class		9.45%	8.30%	8.47%
Investor Class | Return After Taxes on Distributions		8.26%	6.86%	7.07%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		6.32%	6.48%	6.76%
MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	2.60%	2.63%	4.97%
MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)	[1]	5.46%	4.39%	4.09%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

[1] Effective January 31, 2016, the management fee was reduced from 1.95% to 1.75%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch International Opportunities Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH INTERNATIONAL OPPORTUNITIES FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 25% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

25.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in foreign micro cap companies.
Under normal market conditions, we will invest the Fund’s assets in the equity securities of foreign companies with market capitalizations of less than US$1 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). Under normal market conditions, the Fund will invest in at least five of the countries included in the Morgan Stanley Capital International (MSCI) All Country (AC) World Ex-U.S.A. Small Cap Index.
The Fund may invest a significant amount of its total assets (20% to 70% under normal market conditions) at the time of purchase in securities issued by companies domiciled in emerging markets. Emerging market countries are those currently included in the MSCI EFM (Emerging + Frontier Markets) Index. These companies typically are located in the Asia-Pacific region, Eastern Europe, the Middle East, Central and South America, and Africa.
We travel extensively outside of the U.S. to visit companies and expect to meet with senior management. We use a process of quantitative screening followed by “bottom-up” fundamental analysis to identify individual companies that we believe have above average revenue and earnings growth potential. We may invest in early stage companies if we believe they have outstanding long-term growth potential.
We do not use allocation models to restrict the Fund’s investments to certain regions, countries or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, health care, industrials, information technology and materials.
The Fund may also invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Micro Cap Company Stock Risk. Micro cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of micro cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH INTERNATIONAL OPPORTUNITIES FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	44.35%
Worst — 9/30/2008	-27.60%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Institutional Class | Wasatch International Opportunities Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.75%

^[1]

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.21%

^[2]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.96%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[3]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.95%

1 Year

rr_ExpenseExampleYear01

$ 198

3 Years

rr_ExpenseExampleYear03

614

5 Years

rr_ExpenseExampleYear05

1,056

10 Years

rr_ExpenseExampleYear10

$ 2,284

Institutional Class | Wasatch International Opportunities Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2006

rr_AnnualReturn2006

31.50%

2007

rr_AnnualReturn2007

15.17%

2008

rr_AnnualReturn2008

(54.73%)

2009

rr_AnnualReturn2009

75.05%

2010

rr_AnnualReturn2010

26.10%

2011

rr_AnnualReturn2011

(16.01%)

2012

rr_AnnualReturn2012

31.79%

2013

rr_AnnualReturn2013

19.33%

2014

rr_AnnualReturn2014

3.07%

2015

rr_AnnualReturn2015

9.45%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

44.35%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.60%)

1 Year

rr_AverageAnnualReturnYear01

9.45%

5 Years

rr_AverageAnnualReturnYear05

8.30%

10 Years

rr_AverageAnnualReturnYear10

8.47%

Institutional Class | Wasatch International Opportunities Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.26%

5 Years

rr_AverageAnnualReturnYear05

6.86%

10 Years

rr_AverageAnnualReturnYear10

7.07%

Institutional Class | Wasatch International Opportunities Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.32%

5 Years

rr_AverageAnnualReturnYear05

6.48%

10 Years

rr_AverageAnnualReturnYear10

6.76%

Institutional Class | Wasatch International Opportunities Fund | MSCI AC World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.60%

^[4]

5 Years

rr_AverageAnnualReturnYear05

2.63%

^[4]

10 Years

rr_AverageAnnualReturnYear10

4.97%

^[4]

Institutional Class | Wasatch International Opportunities Fund | MSCI World Ex-U.S.A. Small Cap Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.46%

^[4]

5 Years

rr_AverageAnnualReturnYear05

4.39%

^[4]

10 Years

rr_AverageAnnualReturnYear10

4.09%

^[4]

[1] Effective January 31, 2016, the management fee was reduced from 1.95% to 1.75%. The management fee and total annual fund operating expenses have been restated to reflect the current management fee.

[2] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[3] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[4] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

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Institutional Class | Wasatch Large Cap Value Fund

WASATCH LARGE CAP VALUE FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund's investment objectives are to seek capital appreciation and income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Large Cap Value Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Large Cap Value Fund Institutional Class Shares
Management Fee	0.90%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.54%
Total Annual Fund Operating Expenses	1.44%
Expense Reimbursement	(0.49%)	[1]
Total Annual Fund Operating Expenses After Expense Reimbursement	0.95%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Large Cap Value Fund | Institutional Class | USD ($)	97	407	740	1,682

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies with market capitalizations of over $5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
To achieve the Fund’s investment objectives, the Fund typically invests in the securities of companies that we believe will pay above average dividends or interest, but which remain appropriately valued based on our valuation analysis.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios, such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including consumer staples, energy, financials, health care, industrials, information technology and utilities.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Utilities Sector Risk. The utilities sector can be significantly affected by government regulation, interest rate changes, financing difficulties, supply and demand of services or fuel, intense competition, natural resource conservation, and commodity price fluctuations.

HISTORICAL PERFORMANCE

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LARGE CAP VALUE FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2013	10.93%
Worst — 9/30/2015	-8.80%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Large Cap Value Fund	1 Year	Since Inception	Inception Date
Institutional Class	(3.11%)	8.33%	Jan. 31, 2012
Institutional Class | Return After Taxes on Distributions	(5.56%)	3.72%	Jan. 31, 2012
Institutional Class | Return After Taxes on Distributions and Sale of Fund Shares	0.30%	6.57%	Jan. 31, 2012
Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)	(3.83%)	13.39%	Jan. 31, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Large Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LARGE CAP VALUE FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund's investment objectives are to seek capital appreciation and income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of companies with market capitalizations of over $5 billion at the time of purchase. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
To achieve the Fund’s investment objectives, the Fund typically invests in the securities of companies that we believe will pay above average dividends or interest, but which remain appropriately valued based on our valuation analysis.
When evaluating a potential investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. The initial valuation review may include:

• Calculating and reviewing standard ratios, such as price-to-sales, price-to-book, price-to-earnings, and price/earnings-to-growth.
• Modified discounted cash flow models with sensitivity analysis for changes to revenue growth rates, operating margins, outstanding share counts, earnings multiples, and tangible book value.
• Changing sector and company specific outlooks due to subjective factors, including globalization of capital, labor and process knowledge, as well as increasing information and price transparency.

The Fund may invest a large percentage of its assets in a few sectors, including consumer staples, energy, financials, health care, industrials, information technology and utilities.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer staples, energy, financials, health care, industrials, information technology and utilities.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Utilities Sector Risk. The utilities sector can be significantly affected by government regulation, interest rate changes, financing difficulties, supply and demand of services or fuel, intense competition, natural resource conservation, and commodity price fluctuations.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LARGE CAP VALUE FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/2013	10.93%
Worst — 9/30/2015	-8.80%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund's returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Large Cap Value Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

0.90%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.54%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.44%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.49%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.95%

1 Year

rr_ExpenseExampleYear01

$ 97

3 Years

rr_ExpenseExampleYear03

407

5 Years

rr_ExpenseExampleYear05

740

10 Years

rr_ExpenseExampleYear10

$ 1,682

2013

rr_AnnualReturn2013

25.96%

2014

rr_AnnualReturn2014

5.98%

2015

rr_AnnualReturn2015

(3.11%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2013

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

10.93%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(8.80%)

1 Year

rr_AverageAnnualReturnYear01

(3.11%)

Since Inception

rr_AverageAnnualReturnSinceInception

8.33%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Large Cap Value Fund | Return After Taxes on Distributions | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.56%)

Since Inception

rr_AverageAnnualReturnSinceInception

3.72%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Large Cap Value Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.30%

Since Inception

rr_AverageAnnualReturnSinceInception

6.57%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Large Cap Value Fund | Russell 1000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(3.83%)

Since Inception

rr_AverageAnnualReturnSinceInception

13.39%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 0.95% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch Long/Short Fund

WASATCH LONG/SHORT FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is capital appreciation.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Long/Short Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Long/Short Fund Institutional Class Shares
Management Fee	1.10%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.06%
Dividend Expense on Short Sales/Interest Expense	0.31%	[1]
Total Annual Fund Operating Expenses	1.47%
Expense Reimbursement	(0.01%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.46%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Long/Short Fund | Institutional Class | USD ($)	149	464	802	1,756

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets. The Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. We believe opportunities to buy stocks or sell stocks short arise due to a variety of market inefficiencies, including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.

When evaluating long investments, we typically look for stocks that are appropriately valued or undervalued based on our analysis.
When evaluating a short investment, we typically look for signs of current overvaluation. For example, we look for companies that we believe:

• Have earnings that appear to be reflected in the current stock price.
• Are likely to fall short of market expectations.
• Are in industries that exhibit weakness.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.

The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.
The Fund is expected to have a high portfolio turnover rate.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund can make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a Fund’s returns or increase volatility.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security's value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of fund generally has high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

HISTORICAL PERFORMANCE

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk, and to a secondary benchmark (the Citigroup U.S. Domestic 3-Month U.S. Treasury Bills Index), which reflects short-term interest rates and is usually free from the risk of principal fluctuation. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH LONG/SHORT FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2013	9.27%
Worst — 9/30/2015	-12.20%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Long/Short Fund	1 Year	Since Inception	Inception Date
Institutional Class	(16.09%)	(0.50%)	Dec. 13, 2012
Institutional Class | Return After Taxes on Distributions	(18.09%)	(1.93%)	Dec. 13, 2012
Institutional Class | Return After Taxes on Distributions and Sale of Fund Shares	(7.44%)	(0.26%)	Dec. 13, 2012
S&P 500® Index (reflects no deductions for fees, expenses or taxes)	1.38%	14.84%	Dec. 13, 2012
Citigroup U.S. Domestic 3-Month Treasury Bills Index (reflects no deductions for fees, expenses or taxes)	0.03%	0.04%	Dec. 13, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid to brokers varies by security.

[2] Wasatch Advisors, Inc. (Advisor), the Fund’s investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.15% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract’s expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Long/Short Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH LONG/SHORT FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

44.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in equity securities by maintaining long equity positions and short equity positions.
We seek to achieve higher risk-adjusted returns with lower volatility compared to the equity markets in general (as represented by the S&P 500 Index). Under normal market conditions, we will invest the Fund’s assets in the equity securities of companies with market capitalizations of at least $100 million at the time of purchase that we have identified as being undervalued (long equity positions) and we will sell short those securities (short equity positions) that we have identified as being overvalued. The equity securities in which the Fund invests include common stocks, preferred stocks, securities convertible into or exchangeable for common stocks, warrants and any rights to purchase common stocks and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds).
The Fund may at any time have either a net long exposure or a net short exposure to the equity markets. The Fund will not be managed to maintain either net long or net short market exposure.
The Fund may invest in early stage companies and initial public offerings (IPOs).
We believe that the best opportunities to make both short and long equity investments are when the market’s perception of the values of individual companies (measured by the stock price) differs widely from our assessment of the intrinsic values of such companies. When evaluating a potential long or short investment for the Fund, we employ a comprehensive valuation analysis intended to establish a range for fair valuation or intrinsic company value, with a particular emphasis on company fundamentals. We believe opportunities to buy stocks or sell stocks short arise due to a variety of market inefficiencies, including:

• Changes in market participant psychology and circumstances.
• Imperfect information.
• Forecasts and projections by Wall Street analysts and company representatives that differ from experienced reality.

When evaluating long investments, we typically look for stocks that are appropriately valued or undervalued based on our analysis.
When evaluating a short investment, we typically look for signs of current overvaluation. For example, we look for companies that we believe:

• Have earnings that appear to be reflected in the current stock price.
• Are likely to fall short of market expectations.
• Are in industries that exhibit weakness.
• Have poor management.
• Are likely to suffer an event affecting long-term earnings.

The Fund may invest in fixed income securities of any maturity consisting of corporate notes, bonds and debentures, including those that are rated less than investment grade at the time of purchase.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.
The Fund is expected to have a high portfolio turnover rate.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology and materials.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Market Direction Risk. Since the Fund has both a “long” and a “short” portfolio, an investment in the Fund will involve market risks associated with different investment decisions than those made for a typical “long only” stock fund. The Fund’s results will suffer both when there is a general stock market advance and the Fund holds significant “short” equity positions, or when there is a general stock market decline and the Fund holds significant “long” equity positions.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Short Sales Risk. The Fund can make short sales of securities, which means it may experience a loss if the market price of the security increases between the date of the short sale and the date the security is replaced. Short sales may reduce a Fund’s returns or increase volatility.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Interest Rate Risk. Interest rate risk is the risk that a debt security's value will decline due to changes in market interest rates. Even though some interest-bearing securities offer a stable stream of income, their prices will still fluctuate with changes in interest rates. The Fund may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates and the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. When interest rates change, the values of longer duration debt securities usually change more than the values of shorter-duration debt securities.
Credit Risk. Credit risk is the risk that the issuer of a debt security will fail to repay principal and interest on the security when due. Credit risk is affected by the issuer’s credit status, and is generally higher for non-investment grade securities.
Non-Investment Grade Securities Risk. Non-investment grade securities (also known as “high yield” or “junk bonds”), those rated below investment grade by the primary rating agencies (e.g., below BB/Ba by S&P/Moody’s) tend to have more volatile prices and increased price sensitivity to changing interest rates and adverse economic and business developments than investment grade securities. In addition, compared to investments in investment grade securities, investments in non-investment grade securities are subject to greater risk of loss due to default by the issuer or decline in the issuer’s credit quality. There is a greater likelihood that adverse economic or company-specific events will make the issuer unable to make interest and/or principal payments, and more susceptible to negative market sentiment, leading to depressed prices and decreased liquidity for the non-investment grade securities.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Materials Sector Risk. Changes in world events, political, environmental and economic conditions, energy conservation, environmental policies, commodity price volatility, changes in exchange rates, imposition of import controls, increased competition, depletion of resources, and labor relations may adversely affect companies engaged in the production and distribution of materials.
Portfolio Turnover Rate. The Fund’s portfolio turnover rate is expected to exceed 200%. This type of fund generally has high portfolio turnover that necessarily results in greater transaction costs and causes more short-term capital gains (or losses) to be realized. Distributions to shareholders of short-term capital gains are taxed as ordinary income under federal income tax laws.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Institutional Class of the Fund has performed over time. The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the years shown in the bar chart. The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk, and to a secondary benchmark (the Citigroup U.S. Domestic 3-Month U.S. Treasury Bills Index), which reflects short-term interest rates and is usually free from the risk of principal fluctuation. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk,

Performance Additional Market Index [Text]

rr_PerformanceAdditionalMarketIndex

The average annual total returns table allows you to compare the Fund’s performance over the time periods indicated to the primary benchmark (the S&P 500 Index), which reflects the effects of general stock market risk, and to a secondary benchmark (the Citigroup U.S. Domestic 3-Month U.S. Treasury Bills Index), which reflects short-term interest rates and is usually free from the risk of principal fluctuation.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH LONG/SHORT FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/2013	9.27%
Worst — 9/30/2015	-12.20%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Long/Short Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.10%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Dividend Expense on Short Sales/Interest Expense

rr_Component1OtherExpensesOverAssets

0.31%

^[1]

Other Expenses

rr_OtherExpensesOverAssets

0.06%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.47%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.46%

1 Year

rr_ExpenseExampleYear01

$ 149

3 Years

rr_ExpenseExampleYear03

464

5 Years

rr_ExpenseExampleYear05

802

10 Years

rr_ExpenseExampleYear10

$ 1,756

2013

rr_AnnualReturn2013

19.12%

2014

rr_AnnualReturn2014

(2.14%)

2015

rr_AnnualReturn2015

(16.09%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2013

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

9.27%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(12.20%)

1 Year

rr_AverageAnnualReturnYear01

(16.09%)

Since Inception

rr_AverageAnnualReturnSinceInception

(0.50%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Institutional Class | Wasatch Long/Short Fund | Return After Taxes on Distributions | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(18.09%)

Since Inception

rr_AverageAnnualReturnSinceInception

(1.93%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Institutional Class | Wasatch Long/Short Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(7.44%)

Since Inception

rr_AverageAnnualReturnSinceInception

(0.26%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Institutional Class | Wasatch Long/Short Fund | S&P 500® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.38%

Since Inception

rr_AverageAnnualReturnSinceInception

14.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

Institutional Class | Wasatch Long/Short Fund | Citigroup U.S. Domestic 3-Month Treasury Bills Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.03%

Since Inception

rr_AverageAnnualReturnSinceInception

0.04%

Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 13, 2012

[1] Dividends on short sales are the dividends paid to the lenders of borrowed securities. The expenses related to dividends on short sales are estimated and will vary depending on whether the securities the Fund sells short pay dividends and on the amount of any such dividends. Expenses also include borrowing costs paid to the broker in connection with borrowing the security to be sold short. The rate paid to brokers varies by security.

[2] Wasatch Advisors, Inc. (Advisor), the Fund’s investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.15% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract’s expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch Small Cap Growth Fund

WASATCH SMALL CAP GROWTH FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s primary investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Small Cap Growth Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Small Cap Growth Fund Institutional Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.09%	[1]
Total Annual Fund Operating Expenses	1.09%
Expense Reimbursement	(0.04%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.05%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Small Cap Growth Fund | Institutional Class | USD ($)	107	343	598	1,326

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 31% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small growth companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
Within the Fund’s portfolio, we seek to create a blend of “core” companies that we believe have the potential to grow steadily over long periods of time at faster rates than average large companies, and “high growth” companies that we believe have the potential to grow faster and more aggressively than core companies. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe have superior growth prospects. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	25.04%
Worst — 12/31/2008	-22.04%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Small Cap Growth Fund	1 Year	5 Years	10 Years
Investor Class	(0.55%)	9.36%	7.47%
Investor Class | Return After Taxes on Distributions	(4.19%)	7.58%	6.29%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares	2.77%	7.50%	6.12%
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)	(1.38%)	10.67%	7.95%
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	(4.41%)	9.19%	6.80%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund’s investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract’s expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Small Cap Growth Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP GROWTH FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s primary investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 31% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

31.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund’s Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small growth companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
Within the Fund’s portfolio, we seek to create a blend of “core” companies that we believe have the potential to grow steadily over long periods of time at faster rates than average large companies, and “high growth” companies that we believe have the potential to grow faster and more aggressively than core companies. The Fund’s secondary objective of income is achieved when fast growing portfolio companies pay dividends, generated by cash flow, typically after achieving growth targets.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe have superior growth prospects. Our analysis may include studying a company’s financial statements, building proprietary financial models, visiting company facilities, and meeting with executive management, suppliers and customers.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.
The Fund may invest in initial public offerings (IPOs).

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Growth Stock Risk. Growth stock prices may be more sensitive to changes in companies’ current or expected earnings than the prices of other stocks, and growth stock prices may fall or may not appreciate in step with the broader securities markets.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Initial Public Offerings (IPOs) Risk. IPOs involve a higher degree of risk because companies involved in IPOs generally have limited operating histories and their prospects for future profitability are uncertain. Prices of IPOs may also be unstable due to the absence of a prior public market, the small number of shares available for trading and limited investor information.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH SMALL CAP GROWTH FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	25.04%
Worst — 12/31/2008	-22.04%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Small Cap Growth Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.09%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.09%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.04%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.05%

1 Year

rr_ExpenseExampleYear01

$ 107

3 Years

rr_ExpenseExampleYear03

343

5 Years

rr_ExpenseExampleYear05

598

10 Years

rr_ExpenseExampleYear10

$ 1,326

Institutional Class | Wasatch Small Cap Growth Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2006

rr_AnnualReturn2006

8.40%

2007

rr_AnnualReturn2007

8.36%

2008

rr_AnnualReturn2008

(41.66%)

2009

rr_AnnualReturn2009

48.74%

2010

rr_AnnualReturn2010

28.92%

2011

rr_AnnualReturn2011

(0.06%)

2012

rr_AnnualReturn2012

16.95%

2013

rr_AnnualReturn2013

31.17%

2014

rr_AnnualReturn2014

2.61%

2015

rr_AnnualReturn2015

(0.55%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

25.04%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(22.04%)

1 Year

rr_AverageAnnualReturnYear01

(0.55%)

5 Years

rr_AverageAnnualReturnYear05

9.36%

10 Years

rr_AverageAnnualReturnYear10

7.47%

Institutional Class | Wasatch Small Cap Growth Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.19%)

5 Years

rr_AverageAnnualReturnYear05

7.58%

10 Years

rr_AverageAnnualReturnYear10

6.29%

Institutional Class | Wasatch Small Cap Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.77%

5 Years

rr_AverageAnnualReturnYear05

7.50%

10 Years

rr_AverageAnnualReturnYear10

6.12%

Institutional Class | Wasatch Small Cap Growth Fund | Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.38%)

5 Years

rr_AverageAnnualReturnYear05

10.67%

10 Years

rr_AverageAnnualReturnYear10

7.95%

Institutional Class | Wasatch Small Cap Growth Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.41%)

5 Years

rr_AverageAnnualReturnYear05

9.19%

10 Years

rr_AverageAnnualReturnYear10

6.80%

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund’s investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract’s expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch Small Cap Value Fund

WASATCH SMALL CAP VALUE FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch Small Cap Value Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch Small Cap Value Fund Institutional Class Shares
Management Fee	1.00%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.20%
Total Annual Fund Operating Expenses	1.20%
Expense Reimbursement	(0.15%)	[1]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.05%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch Small Cap Value Fund | Institutional Class | USD ($)	107	366	645	1,441

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 57% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate. The Fund’s secondary objective of income is achieved when portfolio companies pay dividends.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

HISTORICAL PERFORMANCE

The following tables provide information on how the Institutional Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

WASATCH SMALL CAP VALUE FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 3/31/2013	10.17%
Worst — 9/30/2015	-10.35%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch Small Cap Value Fund	1 Year	Since Inception	Inception Date
Institutional Class	0.23%	13.20%	Jan. 31, 2012
Institutional Class | Return After Taxes on Distributions	0.10%	13.16%	Jan. 31, 2012
Institutional Class | Return After Taxes on Distributions and Sale of Fund Shares	0.24%	10.46%	Jan. 31, 2012
Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)	(7.47%)	9.69%	Jan. 31, 2012
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)	(4.41%)	11.16%	Jan. 31, 2012

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch Small Cap Value Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH SMALL CAP VALUE FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

Income is a secondary objective, but only when consistent with long-term growth of capital. Currently, we do not expect the Fund’s investments to generate substantial income.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 57% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

57.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in small companies.
Under normal market conditions, we will invest at least 80% of the Fund’s net assets (plus borrowings for investment purposes) in the equity securities of small-capitalization companies. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). The Fund considers a company to be a small-capitalization company if its market capitalization, at the time of purchase, is less than the larger of $3 billion or the market capitalization of the largest company in the Russell 2000 Index as of its most recent reconstitution date. The Russell 2000 Index reconstitution date is typically each year on or around July 1. As of the 2015 reconstitution date, the market capitalization of the largest company in the Russell 2000 Index is $4.7 billion. The market capitalization of the largest company in the Russell 2000 Index is subject to change at its next reconstitution date.
The Fund may invest up to 20% of its total assets at the time of purchase in securities issued by foreign companies in developed or emerging markets. Securities issued by companies incorporated outside the United States whose securities are principally traded in the United States are not defined as foreign companies and are not subject to this limitation.
The Fund may also invest in growth companies if the Advisor believes that current valuation is at a sufficient discount to the projected long-term earnings growth rate. The Fund’s secondary objective of income is achieved when portfolio companies pay dividends.
We use a “bottom-up” process of fundamental analysis to look for individual companies that we believe are temporarily undervalued but have significant potential for stock price appreciation. Our analysis may include studying a company’s financial statements, visiting company facilities, and meeting with executive management, suppliers and customers.
We typically look for companies that we believe fall into one of these three categories at the time of purchase:

• Undiscovered Gems — Companies with good growth potential which have yet to be broadly discovered by Wall Street analysts, thus leaving them attractively undervalued relative to their expected growth.
• Fallen Angels — High quality growth companies that have experienced a temporary setback and therefore have appealing valuations relative to their long term growth potential.
• Quality Value — Quality companies with earnings potential that is not fully reflected in their stock prices.

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, energy, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Small Company Stock Risk. Small-cap stocks may be very sensitive to changing economic conditions and market downturns because the issuers often have narrow markets for their products or services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small-cap companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Value Investing Risk. A value investing strategy attempts to identify strong companies with stocks selling at a discount from their perceived true worth. It is subject to the risk that the stocks’ intrinsic values may never be fully recognized or realized by the market, their prices may go down, or that stocks judged to be undervalued may actually be appropriately priced.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Energy Sector Risk. The value of energy companies is particularly vulnerable to developments in the energy sector, fluctuations in the price and supply of energy fuels, energy conservation, the supply of and demand for specific energy-related products or services, and tax policy and other government regulation.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following tables provide information on how the Institutional Class of the Fund has performed over time. Past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the best and worst quarterly performance of the Fund’s Institutional Class for the calendar years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Institutional Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index and an additional index composed of securities similar to those held by the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Past performance, before and after taxes, of the Fund’s Institutional Class is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH SMALL CAP VALUE FUND — INSTITUTIONAL CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 3/31/2013	10.17%
Worst — 9/30/2015	-10.35%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch Small Cap Value Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.00%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.20%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.20%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.15%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.05%

1 Year

rr_ExpenseExampleYear01

$ 107

3 Years

rr_ExpenseExampleYear03

366

5 Years

rr_ExpenseExampleYear05

645

10 Years

rr_ExpenseExampleYear10

$ 1,441

2013

rr_AnnualReturn2013

38.21%

2014

rr_AnnualReturn2014

7.18%

2015

rr_AnnualReturn2015

0.23%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2013

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

10.17%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(10.35%)

1 Year

rr_AverageAnnualReturnYear01

0.23%

Since Inception

rr_AverageAnnualReturnSinceInception

13.20%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Small Cap Value Fund | Return After Taxes on Distributions | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.10%

Since Inception

rr_AverageAnnualReturnSinceInception

13.16%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Small Cap Value Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.24%

Since Inception

rr_AverageAnnualReturnSinceInception

10.46%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Small Cap Value Fund | Russell 2000® Value Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(7.47%)

Since Inception

rr_AverageAnnualReturnSinceInception

9.69%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

Institutional Class | Wasatch Small Cap Value Fund | Russell 2000® Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(4.41%)

Since Inception

rr_AverageAnnualReturnSinceInception

11.16%

Inception Date

rr_AverageAnnualReturnInceptionDate

Jan. 31, 2012

[1] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.05% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

XML

Institutional Class | Wasatch World Innovators Fund

WASATCH WORLD INNOVATORS FUND® — SUMMARY

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term growth of capital.

FEES AND EXPENSES OF THE FUND

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Shareholder Fees	Institutional Class Wasatch World Innovators Fund Institutional Class Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)	none
Redemption Fee (as a % of amount redeemed on shares held 60 days or less)	2.00%
Exchange Fee	none
Maximum Account Fee	none

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Annual Fund Operating Expenses	Institutional Class Wasatch World Innovators Fund Institutional Class Shares
Management Fee	1.50%
Distribution/Service (12b-1) Fee	none
Other Expenses	0.15%	[1]
Total Annual Fund Operating Expenses	1.65%
Expense Reimbursement	(0.10%)	[2]
Total Annual Fund Operating Expenses After Expense Reimbursement	1.55%

EXAMPLE

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example	1 Year	3 Years	5 Years	10 Years
Institutional Class | Wasatch World Innovators Fund | Institutional Class | USD ($)	158	511	888	1,947

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 100% of the average value of its portfolio.

PRINCIPAL STRATEGIES

The Fund invests primarily in domestic and foreign growth companies that we believe are innovators in their respective sectors or industries.
Modern innovative companies have global business models that are less dependent upon their place of domicile, the location of their headquarters, or the exchange on which their stocks are listed. Under normal market conditions, the Fund will typically be invested in at least three developed countries, including the U.S. The Fund may invest in securities issued by companies domiciled in emerging and frontier markets without limitation.
Under normal market conditions, we expect that a significant portion of the Fund’s assets will be invested in equity securities of companies that have significant non-U.S. economic risk exposure. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). We will consider a company to have significant non-U.S. economic risk exposure if, at the time of purchase, it has at least 50% of its assets outside the U.S., or if at least 50% of its revenues or profits are from goods produced or sold, investments made, or services performed outside the U.S. The Fund may invest a significant portion of its total assets in companies domiciled in foreign companies (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States).
We will use a process of “bottom-up” fundamental analysis to invest in companies of any size. However, because innovative companies are rapidly evolving, we expect to invest a significant portion of the Fund’s assets in early stage companies and small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We have defined two broad categories that we believe are critical to identifying companies with outstanding investment potential. The first is companies that possess valuable intellectual property. The second is companies that are innovators in their respective sectors or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

PRINCIPAL RISKS

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

HISTORICAL PERFORMANCE

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com. Effective April 1, 2011, the Wasatch World Innovators Fund changed its name from the Wasatch Global Science & Technology Fund and changed its principal strategies and primary comparison benchmark index. The bar chart, best and worst quarterly returns and average annual total return table include performance prior to these changes.

WASATCH WORLD INNOVATORS FUND — INVESTOR CLASS
Year by Year Total Returns

Best and Worst Quarterly Returns

Best — 6/30/2009	27.41%
Worst — 12/31/2008	-30.07%

Average Annual Total Returns — (as of 12/31/15)

Average Annual Total Returns - Institutional Class - Wasatch World Innovators Fund		1 Year	5 Years	10 Years
Investor Class		6.20%	11.03%	8.11%
Investor Class | Return After Taxes on Distributions		3.15%	9.54%	7.10%
Investor Class | Return After Taxes on Distributions and Sale of Fund Shares		6.09%	8.77%	6.55%
MSCI AC World Investable Markets Index (reflects no deductions for fees, expenses or taxes)	[1]	(2.19%)	6.11%	4.99%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.55% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[1] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WASATCH FUNDS TRUST

Prospectus Date

rr_ProspectusDate

Jan. 31, 2016

Institutional Class | Wasatch World Innovators Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

WASATCH WORLD INNOVATORS FUND® — SUMMARY

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund’s investment objective is long-term growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The tables below describe the fees and expenses that you may pay if you buy, sell or hold Institutional Class shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

January 31, 2017

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). Higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate, as represented by the Fund’s Investor Class, was 100% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

100.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund’s Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Institutional Class of the Fund with the cost of investing in other mutual funds. The example assumes that you invested $10,000 in the Institutional Class of the Fund for the time periods indicated and then redeemed all of your shares at the end of those periods. The example also assumes that your investment had a 5% return each year and that operating expenses (as a percentage of net assets) of the Fund’s Institutional Class remained the same. This example reflects contractual fee waivers and reimbursements through January 31, 2017. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL STRATEGIES

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in domestic and foreign growth companies that we believe are innovators in their respective sectors or industries.
Modern innovative companies have global business models that are less dependent upon their place of domicile, the location of their headquarters, or the exchange on which their stocks are listed. Under normal market conditions, the Fund will typically be invested in at least three developed countries, including the U.S. The Fund may invest in securities issued by companies domiciled in emerging and frontier markets without limitation.
Under normal market conditions, we expect that a significant portion of the Fund’s assets will be invested in equity securities of companies that have significant non-U.S. economic risk exposure. Equity securities include common stock, preferred stock and securities convertible into common stock, warrants and rights, and other securities with equity characteristics (for example, participatory notes or derivatives linked to a basket of underlying equity securities, certain options on common stock, and exchange-traded funds). We will consider a company to have significant non-U.S. economic risk exposure if, at the time of purchase, it has at least 50% of its assets outside the U.S., or if at least 50% of its revenues or profits are from goods produced or sold, investments made, or services performed outside the U.S. The Fund may invest a significant portion of its total assets in companies domiciled in foreign companies (under normal market conditions, at least 40% of its assets outside the United States, or if conditions are not favorable, 30% of its assets outside the United States).
We will use a process of “bottom-up” fundamental analysis to invest in companies of any size. However, because innovative companies are rapidly evolving, we expect to invest a significant portion of the Fund’s assets in early stage companies and small to mid-size companies with market capitalizations of less than US$5 billion at the time of purchase.
We have defined two broad categories that we believe are critical to identifying companies with outstanding investment potential. The first is companies that possess valuable intellectual property. The second is companies that are innovators in their respective sectors or industries.
The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

The Fund may invest a large percentage of its assets in a few sectors, including consumer discretionary, consumer staples, financials, health care, industrials and information technology.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
The Fund is subject to the following principal investment risks:
Stock Market Risk. The Fund’s investments may decline in value due to movements in the overall stock market.
Stock Selection Risk. The Fund’s investments may decline in value even when the overall stock market is not in a general decline.
Foreign Securities Risk. Foreign securities are generally more volatile and less liquid than U.S. securities. Further, foreign securities may be subject to additional risks not associated with investments in U.S. securities. Differences in the economic and political environment, the amount of available public information, the degree of market regulation, and financial reporting, accounting and auditing standards, and, in the case of foreign currency-denominated securities, fluctuations in currency exchange rates, can have a significant effect on the value of a foreign security.
Emerging and Frontier Markets Risk. In addition to the risks of investing in foreign securities in general, the risks of investing in the securities of companies domiciled in emerging and frontier market countries include increased political or social instability, economies based on only a few industries, unstable currencies, runaway inflation, highly volatile securities markets, unpredictable shifts in policies relating to foreign investments, lack of protection for investors against parties that fail to complete transactions, and the potential for government seizure of assets or nationalization of companies.
Smaller Company Stock Risk. Small- and mid-cap stocks may be very sensitive to changing economic conditions and market downturns. In particular, the issuers of small company stocks have more narrow markets for their products and services, fewer product lines, and more limited managerial and financial resources than larger issuers. The stocks of small companies may therefore be more volatile and the ability to sell these stocks at a desirable time or price may be more limited.
Sector Weightings Risk. To the extent the Fund emphasizes, from time to time, investments in a particular sector, the Fund will be subject to a greater degree to the risks particular to that sector, including the sectors described below. Market conditions, interest rates, and economic, regulatory, or financial developments could significantly affect all the securities in a single sector. If the Fund invests in a few sectors, it may have increased exposure to the price movements of those sectors.
Consumer Discretionary Sector Risk. Industries in the consumer discretionary sector, such as consumer durables, hotels, restaurants, media, retailing, and automobiles, may be significantly impacted by the performance of the overall economy, interest rates, competition, consumer confidence and spending, and changes in demographics and consumer tastes.
Consumer Staples Sector Risk. The consumer staples sector may be affected by marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.
Financials Sector Risk. The financials sector is subject to extensive government regulation, can be subject to relatively rapid change due to increasingly blurred distinctions between service segments, and can be significantly affected by the availability and cost of capital funds, changes in interest rates, the rate of corporate and consumer debt defaults, and price competition.
Health Care Sector Risk. Health care companies are strongly affected by worldwide scientific or technological developments. Their products may rapidly become obsolete. Many health care companies are also subject to significant government regulation and may be affected by changes in government policies.
Industrials Sector Risk. Industries in the industrials sector include companies engaged in the production, distribution or service of products or equipment for manufacturing, agriculture, forestry, mining, and construction, and can be significantly affected by general economic trends, including such factors as employment and economic growth, interest rate changes, changes in consumer spending, legislative and government regulation and spending, import controls, commodity prices, and worldwide competition.
Information Technology Sector Risk. Stocks of information technology companies may be volatile because issuers are sensitive to rapid obsolescence of existing technology, short product cycles, falling prices and profits, competition from new market entrants, and general economic conditions. Information technology stocks, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market.
Early Stage Companies Risk. Early stage companies may never obtain necessary financing, may rely on untested business plans, may not be successful in developing markets for their products or services, and may remain an insignificant part of their industry, and as such may never be profitable. Stocks of early stage companies may be illiquid, privately traded, and more volatile and speculative than the securities of larger companies.

Risk Lose Money [Text]

rr_RiskLoseMoney

All investments carry some degree of risk that will affect the value of the Fund, its investment performance and the price of its shares. As a result, you may lose money if you invest in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

HISTORICAL PERFORMANCE

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Institutional Class is new and has no performance history. ​The following tables provide information on how the Investor Class shares of the Fund have performed over time. The calendar year returns in the bar chart, the best and worst quarterly returns and the average annual total returns table are based on the Fund’s Investor Class shares. Investor Class shares are not offered in this Prospectus. Performance for Investor Class shares would be similar to that for Institutional Class shares because the shares are invested in the same portfolio of securities and would differ only to the extent that Institutional Class shares have different expenses. The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The table below is designed to help you evaluate your risk tolerance by showing the Fund’s best and worst quarterly performance for the years shown in the bar chart. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index. Performance information is updated regularly and is available on the Fund’s website www.WasatchFunds.com. Effective April 1, 2011, the Wasatch World Innovators Fund changed its name from the Wasatch Global Science & Technology Fund and changed its principal strategies and primary comparison benchmark index. The bar chart, best and worst quarterly returns and average annual total return table include performance prior to these changes.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year, as represented by the Investor Class of the Fund. The average annual total return table below allows you to compare the Fund’s performance over the time periods indicated to that of a broad-based market index.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The Institutional Class is new and has no performance history.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.WasatchFunds.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The past performance, before and after taxes, is not necessarily an indication of how these shares will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

WASATCH WORLD INNOVATORS FUND — INVESTOR CLASS
Year by Year Total Returns

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns

Best — 6/30/2009	27.41%
Worst — 12/31/2008	-30.07%

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

Investor Class shares are not offered in this Prospectus.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns — (as of 12/31/15)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.

The Fund’s returns after taxes on distributions and sale of Fund shares may be higher than returns before taxes and after taxes on distributions because they include the effect of a tax benefit an investor may receive from the capital losses that would have been incurred.

Institutional Class | Wasatch World Innovators Fund | Institutional Class Shares

Risk/Return:

rr_RiskReturnAbstract

Maximum Sales Charge (Load) Imposed on Purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Redemption Fee (as a % of amount redeemed on shares held 60 days or less)

rr_RedemptionFeeOverRedemption

2.00%

Exchange Fee

rr_ExchangeFeeOverRedemption

none

Maximum Account Fee

rr_MaximumAccountFeeOverAssets

none

Management Fee

rr_ManagementFeesOverAssets

1.50%

Distribution/Service (12b-1) Fee

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.15%

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.65%

Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.10%)

^[2]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.55%

1 Year

rr_ExpenseExampleYear01

$ 158

3 Years

rr_ExpenseExampleYear03

511

5 Years

rr_ExpenseExampleYear05

888

10 Years

rr_ExpenseExampleYear10

$ 1,947

Institutional Class | Wasatch World Innovators Fund | Investor Class

Risk/Return:

rr_RiskReturnAbstract

2006

rr_AnnualReturn2006

15.95%

2007

rr_AnnualReturn2007

13.17%

2008

rr_AnnualReturn2008

(52.75%)

2009

rr_AnnualReturn2009

67.48%

2010

rr_AnnualReturn2010

24.46%

2011

rr_AnnualReturn2011

4.53%

2012

rr_AnnualReturn2012

18.04%

2013

rr_AnnualReturn2013

33.70%

2014

rr_AnnualReturn2014

(3.68%)

2015

rr_AnnualReturn2015

6.20%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

27.41%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(30.07%)

1 Year

rr_AverageAnnualReturnYear01

6.20%

5 Years

rr_AverageAnnualReturnYear05

11.03%

10 Years

rr_AverageAnnualReturnYear10

8.11%

Institutional Class | Wasatch World Innovators Fund | Return After Taxes on Distributions | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.15%

5 Years

rr_AverageAnnualReturnYear05

9.54%

10 Years

rr_AverageAnnualReturnYear10

7.10%

Institutional Class | Wasatch World Innovators Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Class

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.09%

5 Years

rr_AverageAnnualReturnYear05

8.77%

10 Years

rr_AverageAnnualReturnYear10

6.55%

Institutional Class | Wasatch World Innovators Fund | MSCI AC World Investable Markets Index (reflects no deductions for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(2.19%)

^[3]

5 Years

rr_AverageAnnualReturnYear05

6.11%

^[3]

10 Years

rr_AverageAnnualReturnYear10

4.99%

^[3]

[1] Other Expenses for Institutional Class shares are estimated based on the actual expenses of the Fund's Investor Class, less sub-transfer agency fees paid by the Fund for the Investor Class during the most recent fiscal year.

[2] Wasatch Advisors, Inc. (Advisor), the Fund's investment advisor, has contractually agreed to reimburse the Institutional Class shares of the Fund for Total Annual Fund Operating Expenses in excess of 1.55% of average daily net assets until at least January 31, 2017 (excluding interest, dividend expense on short sales/interest expense, taxes, brokerage commissions, other investment related costs, acquired fund fees and expenses, and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of business). The Board of Trustees is the only party that can terminate the contractual limitation prior to the contract's expiration. The Advisor can rescind the contractual limitation on expenses at any time after its expiration date.

[3] Source: MSCI. MSCI makes no express or implied warranties or representations and shall have no liability whatsoever with respect to any MSCI data contained herein. The MSCI data may not be further redistributed or used to create indices or financial products. This report is not approved or produced by MSCI.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	WASATCH FUNDS TRUST
Prospectus Date	rr_ProspectusDate	Jan. 31, 2016
Document Creation Date	dei_DocumentCreationDate	Jan. 28, 2016