485BPOS

As filed with the Securities and Exchange Commission on February 19, 2014

Securities Act registration no. 33-38953

Investment Company Act file no. 811-06279

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 x

Post-Effective Amendment No. 47x

and

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940 x

Amendment No. 49 x

HARRIS ASSOCIATES INVESTMENT TRUST

(Registrant)

Two North La Salle Street, Suite 500

Chicago, Illinois 60602-3790

Telephone number 312/621-0600

Janet L. Reali	Paulita A. Pike
Harris Associates L.P.	K&L Gates LLP
Two North La Salle Street, #500	70 West Madison Street, #3100
Chicago, Illinois 60602	Chicago, Illinois 60602

(Agents for service)

It is proposed that this filing will become effective:

ximmediately upon filing pursuant to rule 485(b)

oon                            pursuant to rule 485(b)

o60 days after filing pursuant to rule 485(a)(1)

oon                            pursuant to rule 485(a)(1)

o75 days after filing pursuant to rule 485(a)(2)

oon                            pursuant to rule 485(a)(2)

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for effectiveness of this post-effective amendment pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Chicago and State of Illinois on February 19, 2014.

HARRIS ASSOCIATES INVESTMENT TRUST
By	/s/ Kristi L. Rowsell
	Kristi L. Rowsell, President

Pursuant to the requirements of the Securities Act of 1933, this post-effective amendment to the registration statement has been signed below by the following persons in the capacities and on the date indicated.

Signature	Title	Date
/s/ Michael J. Friduss*	Trustee
Michael J. Friduss
/s/ Thomas H. Hayden*	Trustee
Thomas H. Hayden
/s/ Christine M. Maki*	Trustee
Christine M. Maki
/s/ Laurence C. Morse*	Trustee
Laurence C. Morse Ph.D.
/s/ Allan J. Reich*	Trustee
Allan J. Reich
/s/ Steven S. Rogers*	Trustee	February 19, 2014
Steven S. Rogers
/s/ Burton W. Ruder*	Trustee
Burton W. Ruder
/s/ Peter S. Voss*	Trustee
Peter S. Voss
/s/ Kristi L. Rowsell	Trustee and President (Principal Executive Officer)
Kristi L. Rowsell
/s/ Thomas E. Herman	Principal Financial Officer
Thomas E. Herman

By	/s/ Janet L. Reali
	Janet L. Reali
	Secretary

* Janet L. Reali signs this document on behalf of the individuals noted pursuant to the powers of attorney filed on January 28, 2014 as exhibit (q) to Post-effective Amendment no. 46 on Form N-1A (File No. 33-38953) and incorporated by reference herein.

Index of Exhibits

Exhibit
Number	Exhibits
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

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

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Oakmark International Small Cap Fund

Objective [Heading]

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INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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Oakmark International Small Cap Fund seeks long-term capital appreciation.

Expense [Heading]

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FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

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Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

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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]

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Portfolio Turnover

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 50% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

50.00%

Expense Example [Heading]

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Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

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The Fund invests primarily in a diversified portfolio of common stocks of non-U.S. companies. Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in the stocks of "small cap companies." A small cap company is one whose market capitalization is no greater than the largest market capitalization of any company included in the S&P EPAC (Europe Pacific Asia Composite) Small Cap Index ($12.4 billion as of December 31, 2013).

The Fund may invest in non-U.S. markets throughout the world, including emerging markets. Ordinarily, the Fund will invest in the securities of at least five countries outside the U.S. There are no geographic limits on the Fund's non-U.S. investments.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to seventy stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry.

Risk [Heading]

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PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

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As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks, thirty to seventy rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Emerging Markets Risk. The risks of investing in non-U.S. securities may be heightened for securities of issuers located in emerging market countries. Emerging market countries tend to have economic structures that are less diverse and mature, and political systems that are less stable, than those of developed countries. In addition to all of the risks of investing in non-U.S. securities, emerging markets are more susceptible to governmental interference, local taxes being imposed on foreign investments, restrictions on gaining access to sales proceeds, and less liquid and efficient trading markets.

Small Cap Securities Risk. Investments in small cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. Therefore, when purchasing and selling smaller cap securities, the Fund may experience higher transactional costs due to the length of time that might be needed to purchase or sell such securities. Additionally, if the Fund is forced to sell securities to meet redemption requests or other cash needs, it may be forced to dispose of those securities under disadvantageous circumstances and at a loss. Smaller companies also may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

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PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

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Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

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Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 43.7%, during the quarter ended June 30, 2009
Lowest quarterly return: -27.3%, during the quarter ended December 31, 2008

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

43.70%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(27.30%)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

MSCI World ex U.S. Small Cap Index

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

25.55%

5 Years

rr_AverageAnnualReturnYear05

18.45%

10 Years

rr_AverageAnnualReturnYear10

9.24%

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

(2.00%)

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

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1.11%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.24%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.35%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 137

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

428

Expense Example, with Redemption, 5 Years

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739

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,624

Annual Return 2004

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28.95%

Annual Return 2005

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21.26%

Annual Return 2006

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34.90%

Annual Return 2007

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(8.33%)

Annual Return 2008

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(45.71%)

Annual Return 2009

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67.45%

Annual Return 2010

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21.53%

Annual Return 2011

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(16.44%)

Annual Return 2012

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18.39%

Annual Return 2013

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27.68%

1 Year

rr_AverageAnnualReturnYear01

27.68%

5 Years

rr_AverageAnnualReturnYear05

20.78%

10 Years

rr_AverageAnnualReturnYear10

10.44%

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

26.39%

5 Years

rr_AverageAnnualReturnYear05

20.52%

10 Years

rr_AverageAnnualReturnYear10

8.96%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.11%

5 Years

rr_AverageAnnualReturnYear05

17.12%

10 Years

rr_AverageAnnualReturnYear10

8.73%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

(2.00%)

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

1.11%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.53%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.64%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

167

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

517

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

892

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,944

1 Year

rr_AverageAnnualReturnYear01

27.24%

5 Years

rr_AverageAnnualReturnYear05

20.43%

10 Years

rr_AverageAnnualReturnYear10

10.22%

XML

Oakmark International Fund

Oakmark International Fund

INVESTMENT OBJECTIVE

Oakmark International Fund seeks long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark International Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee	none	none
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark International Fund	Class I	Class II
Management fees	0.81%	0.81%
Distribution (12b-1) fees	none	none
Other expenses	0.17%	0.53%
Total Annual Fund Operating Expenses	0.98%	1.34%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark International Fund (USD $)	Class I	Class II
1 Year	100	136
3 Years	312	425
5 Years	542	734
10 Years	1,201	1,613

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 37% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

The Fund invests primarily in a diversified portfolio of common stocks of non-U.S. companies. The Fund may invest in non-U.S. markets throughout the world, including emerging markets. Ordinarily, the Fund will invest in the securities of at least five countries outside of the U.S. There are no geographic limits on the Fund's non-U.S. investments. The Fund may invest in securities of large-, mid-, and small- capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks, thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Small and Mid Cap Securities Risk. Investments in small and mid cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, smaller companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 33.2%, during the quarter ended June 30, 2009
Lowest quarterly return: -21.4%, during the quarter ended December 31, 2008

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark International Fund	1 Year	5 Years	10 Years
Class I	29.34%	21.14%	10.50%
Class II	28.96%	20.82%	10.15%
After Taxes on Distributions Class I	28.44%	20.91%	9.54%
After Taxes on Distributions and Sale of Fund Shares Class I	17.23%	17.47%	8.76%
MSCI World ex U.S. Index (does not reflect the deduction of fees, expenses or taxes)	21.02%	12.49%	7.07%

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

XML

Oakmark Select Fund

Oakmark Select Fund

INVESTMENT OBJECTIVE

Oakmark Select Fund seeks long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark Select Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee	none	none
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark Select Fund	Class I	Class II
Management fees	0.88%	0.88%
Distribution (12b-1) fees	none	none
Other expenses	0.13%	0.45%
Total Annual Fund Operating Expenses	1.01%	1.33%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark Select Fund (USD $)	Class I	Class II
1 Year	103	135
3 Years	322	421
5 Years	558	729
10 Years	1,236	1,601

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 24% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

The Fund invests primarily in common stocks of U.S. companies. The Fund is non-diversified, which means that it may invest a greater portion of its assets in a more limited number of issuers than a diversified fund. The Fund could own as few as twelve securities, but generally will have approximately twenty securities in its portfolio and as a result, a higher percentage of the Fund's total assets may also be invested in a particular sector or industry. The Fund generally invests in the securities of large- and mid-capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Non-Diversification Risk. A non-diversified fund (generally, a fund that may invest in a limited number of issuers) may be subject to greater risk than a diversified fund because changes in the financial condition or market assessment of a single issuer may cause greater fluctuation in the value of a non-diversified fund's shares. The Fund could hold as few as twelve securities, but generally will have approximately twenty securities in its portfolio. Lack of broad diversification also may cause a non-diversified fund to be more susceptible to economic, political or regulatory events than a diversified fund. A non-diversification strategy may increase the Fund's volatility.

Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular sector or industry, changes affecting that sector or industry, or the perception of that sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Mid Cap Securities Risk. Investments in mid cap companies may be riskier than investments in larger, more established companies. Mid cap companies may have limited product lines, markets or financial resources or may depend on a few key employees, and may be more susceptible to particular economic events or competitive factors than large capitalization companies. The securities of mid cap companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, mid cap companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 25.7%, during the quarter ended June 30, 2009
Lowest quarterly return: -20.2%, during the quarter ended December 31, 2008

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark Select Fund	1 Year	5 Years	10 Years
Class I	36.52%	24.00%	7.70%
Class II	36.09%	23.68%	7.41%
After Taxes on Distributions Class I	34.81%	23.32%	6.92%
After Taxes on Distributions and Sale of Fund Shares Class I	22.02%	19.91%	6.31%
S&P 500 Index (does not reflect the deduction of fees, expenses or taxes)	32.39%	17.94%	7.41%

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Oakmark International Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Oakmark International Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

Below are the fees and expenses that you would pay if you buy and hold 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). A higher portfolio turnover rate 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 37% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

37.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a diversified portfolio of common stocks of non-U.S. companies. The Fund may invest in non-U.S. markets throughout the world, including emerging markets. Ordinarily, the Fund will invest in the securities of at least five countries outside of the U.S. There are no geographic limits on the Fund's non-U.S. investments. The Fund may invest in securities of large-, mid-, and small- capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry.

Risk [Heading]

rr_RiskHeading

PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks, thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Small and Mid Cap Securities Risk. Investments in small and mid cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, smaller companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 33.2%, during the quarter ended June 30, 2009
Lowest quarterly return: -21.4%, during the quarter ended December 31, 2008

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

33.20%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(21.40%)

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

(does not reflect the deduction of fees, expenses or taxes)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

MSCI World ex U.S. Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

21.02%

5 Years

rr_AverageAnnualReturnYear05

12.49%

10 Years

rr_AverageAnnualReturnYear10

7.07%

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.81%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.17%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.98%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 100

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

312

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

542

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,201

Annual Return 2004

rr_AnnualReturn2004

19.09%

Annual Return 2005

rr_AnnualReturn2005

14.12%

Annual Return 2006

rr_AnnualReturn2006

30.60%

Annual Return 2007

rr_AnnualReturn2007

(0.51%)

Annual Return 2008

rr_AnnualReturn2008

(41.06%)

Annual Return 2009

rr_AnnualReturn2009

56.30%

Annual Return 2010

rr_AnnualReturn2010

16.22%

Annual Return 2011

rr_AnnualReturn2011

(14.07%)

Annual Return 2012

rr_AnnualReturn2012

29.22%

Annual Return 2013

rr_AnnualReturn2013

29.34%

1 Year

rr_AverageAnnualReturnYear01

29.34%

5 Years

rr_AverageAnnualReturnYear05

21.14%

10 Years

rr_AverageAnnualReturnYear10

10.50%

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

28.44%

5 Years

rr_AverageAnnualReturnYear05

20.91%

10 Years

rr_AverageAnnualReturnYear10

9.54%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

17.23%

5 Years

rr_AverageAnnualReturnYear05

17.47%

10 Years

rr_AverageAnnualReturnYear10

8.76%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.81%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.53%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.34%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

136

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

425

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

734

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,613

1 Year

rr_AverageAnnualReturnYear01

28.96%

5 Years

rr_AverageAnnualReturnYear05

20.82%

10 Years

rr_AverageAnnualReturnYear10

10.15%

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Oakmark Global Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Oakmark Global Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

Below are the fees and expenses that you would pay if you buy and hold 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). A higher portfolio turnover rate 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 45% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

45.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a diversified portfolio of common stocks of U.S. and non-U.S. companies. The Fund invests in the securities of companies located in at least three countries. Typically, the Fund invests between 25-75% of its total assets in securities of U.S. companies and between 25-75% of its total assets in securities of non-U.S. companies. There are no geographic limits on the Fund's non-U.S. investments, and the Fund may invest in securities of companies located in developed or emerging markets. The Fund may invest in the securities of large-, mid-, and small-capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry.

Risk [Heading]

rr_RiskHeading

PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks—thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Investments in securities issued by entities domiciled in the United States also may be subject to many of these risks. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Small and Mid Cap Securities Risk. Investments in small and mid cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, smaller companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's average annual returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's average annual returns compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 29.5%, during the quarter ended June 30, 2009
Lowest quarterly return: -24.1%, during the quarter ended December 31, 2008

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

29.50%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(24.10%)

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

(does not reflect the deduction of fees, expenses or taxes)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

MSCI World Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

26.68%

5 Years

rr_AverageAnnualReturnYear05

15.02%

10 Years

rr_AverageAnnualReturnYear10

6.98%

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.97%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.13%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 115

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

359

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

622

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,375

Annual Return 2004

rr_AnnualReturn2004

15.63%

Annual Return 2005

rr_AnnualReturn2005

13.23%

Annual Return 2006

rr_AnnualReturn2006

24.18%

Annual Return 2007

rr_AnnualReturn2007

7.33%

Annual Return 2008

rr_AnnualReturn2008

(38.78%)

Annual Return 2009

rr_AnnualReturn2009

40.19%

Annual Return 2010

rr_AnnualReturn2010

15.74%

Annual Return 2011

rr_AnnualReturn2011

(11.65%)

Annual Return 2012

rr_AnnualReturn2012

20.16%

Annual Return 2013

rr_AnnualReturn2013

34.12%

1 Year

rr_AverageAnnualReturnYear01

34.12%

5 Years

rr_AverageAnnualReturnYear05

18.23%

10 Years

rr_AverageAnnualReturnYear10

9.45%

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

32.45%

5 Years

rr_AverageAnnualReturnYear05

17.86%

10 Years

rr_AverageAnnualReturnYear10

8.71%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

20.07%

5 Years

rr_AverageAnnualReturnYear05

14.82%

10 Years

rr_AverageAnnualReturnYear10

7.86%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.97%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.51%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.48%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

151

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

468

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

808

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,768

1 Year

rr_AverageAnnualReturnYear01

33.67%

5 Years

rr_AverageAnnualReturnYear05

17.83%

10 Years

rr_AverageAnnualReturnYear10

9.08%

XML

Oakmark International Small Cap Fund

Oakmark International Small Cap Fund

INVESTMENT OBJECTIVE

Oakmark International Small Cap Fund seeks long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark International Small Cap Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee (as a percentage of amount redeemed on shares held for 90 days or less)	2.00%	2.00%
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark International Small Cap Fund	Class I	Class II
Management fees	1.11%	1.11%
Distribution (12b-1) fees	none	none
Other expenses	0.24%	0.53%
Total Annual Fund Operating Expenses	1.35%	1.64%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark International Small Cap Fund (USD $)	Class I	Class II
1 Year	137	167
3 Years	428	517
5 Years	739	892
10 Years	1,624	1,944

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 50% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

The Fund invests primarily in a diversified portfolio of common stocks of non-U.S. companies. Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in the stocks of "small cap companies." A small cap company is one whose market capitalization is no greater than the largest market capitalization of any company included in the S&P EPAC (Europe Pacific Asia Composite) Small Cap Index ($12.4 billion as of December 31, 2013).

The Fund may invest in non-U.S. markets throughout the world, including emerging markets. Ordinarily, the Fund will invest in the securities of at least five countries outside the U.S. There are no geographic limits on the Fund's non-U.S. investments.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to seventy stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks, thirty to seventy rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Emerging Markets Risk. The risks of investing in non-U.S. securities may be heightened for securities of issuers located in emerging market countries. Emerging market countries tend to have economic structures that are less diverse and mature, and political systems that are less stable, than those of developed countries. In addition to all of the risks of investing in non-U.S. securities, emerging markets are more susceptible to governmental interference, local taxes being imposed on foreign investments, restrictions on gaining access to sales proceeds, and less liquid and efficient trading markets.

Small Cap Securities Risk. Investments in small cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. Therefore, when purchasing and selling smaller cap securities, the Fund may experience higher transactional costs due to the length of time that might be needed to purchase or sell such securities. Additionally, if the Fund is forced to sell securities to meet redemption requests or other cash needs, it may be forced to dispose of those securities under disadvantageous circumstances and at a loss. Smaller companies also may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 43.7%, during the quarter ended June 30, 2009
Lowest quarterly return: -27.3%, during the quarter ended December 31, 2008

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark International Small Cap Fund	1 Year	5 Years	10 Years
Class I	27.68%	20.78%	10.44%
Class II	27.24%	20.43%	10.22%
After Taxes on Distributions Class I	26.39%	20.52%	8.96%
After Taxes on Distributions and Sale of Fund Shares Class I	16.11%	17.12%	8.73%
MSCI World ex U.S. Small Cap Index	25.55%	18.45%	9.24%

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

XML

Oakmark Global Select Fund

Oakmark Global Select Fund

INVESTMENT OBJECTIVE

Oakmark Global Select Fund seeks long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark Global Select Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee	none	none
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark Global Select Fund	Class I	Class II
Management fees	0.96%	0.96%
Distribution (12b-1) fees	none	none
Other expenses	0.19%	0.44%
Total Annual Fund Operating Expenses	1.15%	1.40%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark Global Select Fund (USD $)	Class I	Class II
1 Year	117	143
3 Years	365	443
5 Years	633	766
10 Years	1,398	1,680

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 INVESTMENT STRATEGY

The Fund invests primarily in common stocks of U.S. and non-U.S. companies. The Fund invests in the securities of companies located in at least three countries. The Fund is non-diversified, which means that it may invest a greater portion of its assets in a more limited number of issuers than a diversified fund. The Fund could own as few as twelve securities, but generally will have approximately twenty securities in its portfolio and as a result, a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry. Typically, the Fund will invest at least 40% of its total assets in securities of non-U.S. companies (unless Harris Associates L.P., the Fund's investment adviser (the "Adviser"), deems market conditions and/or company valuations less favorable to non-U.S. companies, in which case the Fund will invest at least 30% of its total assets in securities of non- U.S. companies). There are no geographic limits on the Fund's non-U.S. investments, and the Fund may invest in securities of companies located in developed or emerging markets. The Fund generally invests in the securities of larger capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Adviser uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Investments in securities issued by entities domiciled in the United States also may be subject to many of these risks. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Non-Diversification Risk. A non-diversified fund (generally, a fund that may invest in a limited number of issuers) may be subject to greater risk than a diversified fund because changes in the financial condition or market assessment of a single issuer may cause greater fluctuation in the value of a non-diversified fund's shares. The Fund could hold as few as twelve securities, but generally will have approximately twenty securities in its portfolio. Lack of broad diversification also may cause a non-diversified fund to be more susceptible to economic, political or regulatory events than a diversified fund. A non-diversification strategy may increase the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2007, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 26.6%, during the quarter ended June 30, 2009
Lowest quarterly return: -16.3%, during the quarter ended December 31, 2008

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark Global Select Fund	1 Year	5 Years	Since Inception	Inception Date
Class I	33.80%	21.64%	9.40%	Oct. 02, 2006
After Taxes on Distributions Class I	33.07%	21.43%	8.91%
After Taxes on Distributions and Sale of Fund Shares Class I	19.79%	17.83%	7.44%
MSCI World Index (does not reflect the deduction of fees, expenses or taxes)	26.68%	15.02%	4.84%	Oct. 02, 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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Oakmark Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Oakmark Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

Below are the fees and expenses that you would pay if you buy and hold 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). A higher portfolio turnover rate 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 19% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

19.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a diversified portfolio of common stocks of U.S. companies. The Fund generally invests in the securities of larger capitalization companies. The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular sector or industry.

Risk [Heading]

rr_RiskHeading

PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks—thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular sector or industry, changes affecting that sector or industry, or the perception of that sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's average annual returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's average annual returns compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 23.2%, during the quarter ended June 30, 2009
Lowest quarterly return: -23.0%, during the quarter ended December 31, 2008

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

23.20%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(23.00%)

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

(does not reflect the deduction of fees, expenses or taxes)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

S&P 500 Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

32.39%

5 Years

rr_AverageAnnualReturnYear05

17.94%

10 Years

rr_AverageAnnualReturnYear10

7.41%

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.81%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.95%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 97

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

303

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

525

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,166

Annual Return 2004

rr_AnnualReturn2004

11.73%

Annual Return 2005

rr_AnnualReturn2005

(1.31%)

Annual Return 2006

rr_AnnualReturn2006

18.26%

Annual Return 2007

rr_AnnualReturn2007

(3.64%)

Annual Return 2008

rr_AnnualReturn2008

(32.61%)

Annual Return 2009

rr_AnnualReturn2009

44.77%

Annual Return 2010

rr_AnnualReturn2010

12.18%

Annual Return 2011

rr_AnnualReturn2011

1.82%

Annual Return 2012

rr_AnnualReturn2012

20.97%

Annual Return 2013

rr_AnnualReturn2013

37.29%

1 Year

rr_AverageAnnualReturnYear01

37.29%

5 Years

rr_AverageAnnualReturnYear05

22.39%

10 Years

rr_AverageAnnualReturnYear10

8.81%

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

35.78%

5 Years

rr_AverageAnnualReturnYear05

21.91%

10 Years

rr_AverageAnnualReturnYear10

8.25%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

22.23%

5 Years

rr_AverageAnnualReturnYear05

18.46%

10 Years

rr_AverageAnnualReturnYear10

7.20%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.81%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.42%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.23%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

125

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

390

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

676

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,489

1 Year

rr_AverageAnnualReturnYear01

36.92%

5 Years

rr_AverageAnnualReturnYear05

22.05%

10 Years

rr_AverageAnnualReturnYear10

8.48%

XML

Oakmark Fund

Oakmark Fund

INVESTMENT OBJECTIVE

Oakmark Fund seeks long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee	none	none
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark Fund	Class I	Class II
Management fees	0.81%	0.81%
Distribution (12b-1) fees	none	none
Other expenses	0.14%	0.42%
Total Annual Fund Operating Expenses	0.95%	1.23%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark Fund (USD $)	Class I	Class II
1 Year	97	125
3 Years	303	390
5 Years	525	676
10 Years	1,166	1,489

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 19% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

The Fund invests primarily in a diversified portfolio of common stocks of U.S. companies. The Fund generally invests in the securities of larger capitalization companies. The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular sector or industry.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks—thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular sector or industry, changes affecting that sector or industry, or the perception of that sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's average annual returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 23.2%, during the quarter ended June 30, 2009
Lowest quarterly return: -23.0%, during the quarter ended December 31, 2008

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark Fund	1 Year	5 Years	10 Years
Class I	37.29%	22.39%	8.81%
Class II	36.92%	22.05%	8.48%
After Taxes on Distributions Class I	35.78%	21.91%	8.25%
After Taxes on Distributions and Sale of Fund Shares Class I	22.23%	18.46%	7.20%
S&P 500 Index (does not reflect the deduction of fees, expenses or taxes)	32.39%	17.94%	7.41%

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Oakmark Equity and Income Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Oakmark Equity and Income Fund seeks income and preservation and growth of capital.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

Below are the fees and expenses that you would pay if you buy and hold 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). A higher portfolio turnover rate 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%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in a diversified portfolio of U.S. equity and debt securities (although the Fund may invest up to 35% of its total assets in equity and debt securities of non-U.S. issuers). The Fund is intended to present a balanced investment program between growth and income by investing approximately 40-75% of its total assets in common stock, including securities convertible into common stock, and up to 60% of its assets in U.S. government securities and debt securities, including inflation-indexed securities, rated at time of purchase within the two highest grades assigned by Moody's Investors Service, Inc. or by Standard & Poor's Corporation Ratings Group, a division of The McGraw-Hill Companies. The Fund also may invest up to 20% of its total assets in unrated or below investment grade rated debt securities, sometimes called junk bonds. The types of equity securities in which the Fund may invest include common and preferred stocks and warrants or other similar rights and convertible securities. The types of debt securities in which the Fund may invest include debt securities of both governmental and corporate issuers. The Fund may invest in the securities of large-, mid-, and small-capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy—Equity Portion of the Fund:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its equity investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular sector or industry.

The proportion of the Fund held in debt securities will vary in light of the Adviser's view of the attractiveness of debt securities. In times when the Adviser believes equities provide above average absolute value, the proportion of the Fund allocated to fixed income will decline. In selecting debt securities, the Adviser considers many factors, including among other things, quality, yield-to-maturity, liquidity, current yield and call risk. The Adviser believes the role of fixed income investments in the Fund is to help buffer the volatility of the Fund's equity portfolio and generate income.

Risk [Heading]

rr_RiskHeading

PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks—thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Small and Mid Cap Securities Risk. Investments in small and mid cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, smaller companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular sector or industry, changes affecting that sector or industry, or the perception of that sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Debt Securities Risk. Debt securities are subject to credit risk, interest rate risk and liquidity risk. Credit risk is the risk the issuer or guarantor of a debt security will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. Interest rate risk is the risk of losses due to changes in interest rates. In general, the prices of debt securities rise when interest rates fall, and the prices fall when interest rates rise. Liquidity risk is the risk a particular security may be difficult to purchase or sell and that the Fund may be unable to sell such security at an advantageous time or price. The Fund's investments in government-sponsored entity securities also exhibit these risks, although the degree of such risks may vary significantly among the different government-sponsored entity securities. Some securities issued or guaranteed by U.S. government agencies or instrumentalities are not backed by the full faith and credit of the U.S. and may only be supported by the right of the agency or instrumentality to borrow from the U.S. Treasury. There can be no assurance that the U.S. government will always provide financial support to those agencies or instrumentalities. Sovereign debt instruments, including U.S. and non-U.S. debt instruments, are subject to the risk that a governmental entity may delay, refuse, or be unable to pay interest or repay principal on its debt. There is no legal process for collecting sovereign debt that a government does not pay, nor are there bankruptcy proceedings through which all or part of the sovereign debt that a government entity has not repaid may be collected. Below investment grade securities (commonly referred to as junk bonds) are regarded as having predominately speculative characteristics and may be more susceptible to credit, interest rate or liquidity risk than a debt security rated investment grade.

Inflation-Indexed Securities Risk. The principal value of an investment by the Fund is not protected or otherwise guaranteed by virtue of the Fund's investments in inflation-indexed bonds. If the index measuring inflation falls, the principal value of inflation-indexed bonds will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced.

Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds. For bonds that do not provide a similar guarantee, the adjusted principal value of the bond repaid at maturity may be less than the original principal value.

The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates are tied to the relationship between nominal interest rates and the rate of inflation. If nominal interest rates increase at a faster rate than inflation, real interest rates may rise, leading to a decrease in value of inflation indexed bonds. Short-term increases in inflation may lead to a decline in value. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

Periodic adjustments for inflation to the principal amount of an inflation-indexed bond may give rise to original issue discount, which will be includable in the Fund's gross income. Due to original issue discount, the Fund may be required to make annual distributions to shareholders that exceed the cash received, which may cause the Fund to liquidate certain investments when it is not advantageous to do so. Also, if the principal value of an inflation-indexed bond is adjusted downward due to deflation, amounts previously distributed in the taxable year may be characterized in some circumstances as a return of capital.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Investments in securities issued by entities domiciled in the United States also may be subject to many of these risks.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 10.6%, during the quarter ended September 30, 2009
Lowest quarterly return: -12.8%, during the quarter ended September 30, 2011

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

10.60%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(12.80%)

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

(does not reflect the deduction of fees, expenses or taxes)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

Lipper Balanced Funds Index is an index of the thirty largest balanced funds tracked by Lipper, Inc. All returns reflect reinvested dividends. This information shows how the Fund's returns compare with the returns of an index comprised of the thirty largest balanced funds tracked by Lipper, Inc.

The S&P 500 Index is a widely quoted, unmanaged, market weighted index that includes 500 of the largest publicly traded companies in the U.S. All returns reflect reinvested dividends. This information shows how the Fund's returns compare with a broad-based securities market index.

The Barclays U.S. Government & Credit Index measures the performance of U.S. dollar-denominated U.S. Treasury bonds, government-related bonds and investment grade U.S. corporate bonds that have a remaining maturity of greater than or equal to one year. This information shows how the Fund's returns compare with a broad-based securities market index.

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

Lipper Balanced Funds Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.39%

5 Years

rr_AverageAnnualReturnYear05

12.62%

10 Years

rr_AverageAnnualReturnYear10

6.19%

S&P 500 Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

32.39%

5 Years

rr_AverageAnnualReturnYear05

17.94%

10 Years

rr_AverageAnnualReturnYear10

7.41%

Barclays U.S. Government/Credit Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(2.36%)

5 Years

rr_AverageAnnualReturnYear05

4.40%

10 Years

rr_AverageAnnualReturnYear10

4.52%

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.66%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.11%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.77%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 79

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

246

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

428

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

954

Annual Return 2004

rr_AnnualReturn2004

10.36%

Annual Return 2005

rr_AnnualReturn2005

8.60%

Annual Return 2006

rr_AnnualReturn2006

10.82%

Annual Return 2007

rr_AnnualReturn2007

11.97%

Annual Return 2008

rr_AnnualReturn2008

(16.18%)

Annual Return 2009

rr_AnnualReturn2009

19.84%

Annual Return 2010

rr_AnnualReturn2010

9.50%

Annual Return 2011

rr_AnnualReturn2011

0.64%

Annual Return 2012

rr_AnnualReturn2012

9.05%

Annual Return 2013

rr_AnnualReturn2013

24.25%

1 Year

rr_AverageAnnualReturnYear01

24.25%

5 Years

rr_AverageAnnualReturnYear05

12.34%

10 Years

rr_AverageAnnualReturnYear10

8.35%

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

21.94%

5 Years

rr_AverageAnnualReturnYear05

11.62%

10 Years

rr_AverageAnnualReturnYear10

7.54%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.56%

5 Years

rr_AverageAnnualReturnYear05

9.93%

10 Years

rr_AverageAnnualReturnYear10

6.79%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.66%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.44%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.10%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

112

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

350

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

606

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,340

1 Year

rr_AverageAnnualReturnYear01

23.83%

5 Years

rr_AverageAnnualReturnYear05

11.98%

10 Years

rr_AverageAnnualReturnYear10

8.02%

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Oakmark Global Select Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Oakmark Global Select Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

Below are the fees and expenses that you would pay if you buy and hold 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). A higher portfolio turnover rate 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%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in common stocks of U.S. and non-U.S. companies. The Fund invests in the securities of companies located in at least three countries. The Fund is non-diversified, which means that it may invest a greater portion of its assets in a more limited number of issuers than a diversified fund. The Fund could own as few as twelve securities, but generally will have approximately twenty securities in its portfolio and as a result, a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry. Typically, the Fund will invest at least 40% of its total assets in securities of non-U.S. companies (unless Harris Associates L.P., the Fund's investment adviser (the "Adviser"), deems market conditions and/or company valuations less favorable to non-U.S. companies, in which case the Fund will invest at least 30% of its total assets in securities of non- U.S. companies). There are no geographic limits on the Fund's non-U.S. investments, and the Fund may invest in securities of companies located in developed or emerging markets. The Fund generally invests in the securities of larger capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Adviser uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

Risk [Heading]

rr_RiskHeading

PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Investments in securities issued by entities domiciled in the United States also may be subject to many of these risks. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Non-Diversification Risk. A non-diversified fund (generally, a fund that may invest in a limited number of issuers) may be subject to greater risk than a diversified fund because changes in the financial condition or market assessment of a single issuer may cause greater fluctuation in the value of a non-diversified fund's shares. The Fund could hold as few as twelve securities, but generally will have approximately twenty securities in its portfolio. Lack of broad diversification also may cause a non-diversified fund to be more susceptible to economic, political or regulatory events than a diversified fund. A non-diversification strategy may increase the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

A non-diversified fund (generally, a fund that may invest in a limited number of issuers) may be subject to greater risk than a diversified fund because changes in the financial condition or market assessment of a single issuer may cause greater fluctuation in the value of a non-diversified fund's shares. The Fund could hold as few as twelve securities, but generally will have approximately twenty securities in its portfolio. Lack of broad diversification also may cause a non-diversified fund to be more susceptible to economic, political or regulatory events than a diversified fund. A non-diversification strategy may increase the Fund's volatility.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Since 2007, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 26.6%, during the quarter ended June 30, 2009
Lowest quarterly return: -16.3%, during the quarter ended December 31, 2008

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

26.60%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.30%)

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

(does not reflect the deduction of fees, expenses or taxes)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

MSCI World Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

26.68%

5 Years

rr_AverageAnnualReturnYear05

15.02%

Since Inception

rr_AverageAnnualReturnSinceInception

4.84%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 02, 2006

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.96%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.19%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.15%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 117

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

365

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

633

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,398

Annual Return 2007

rr_AnnualReturn2007

(1.16%)

Annual Return 2008

rr_AnnualReturn2008

(32.49%)

Annual Return 2009

rr_AnnualReturn2009

53.58%

Annual Return 2010

rr_AnnualReturn2010

11.06%

Annual Return 2011

rr_AnnualReturn2011

(5.87%)

Annual Return 2012

rr_AnnualReturn2012

23.95%

Annual Return 2013

rr_AnnualReturn2013

33.80%

1 Year

rr_AverageAnnualReturnYear01

33.80%

5 Years

rr_AverageAnnualReturnYear05

21.64%

Since Inception

rr_AverageAnnualReturnSinceInception

9.40%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 02, 2006

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

33.07%

5 Years

rr_AverageAnnualReturnYear05

21.43%

Since Inception

rr_AverageAnnualReturnSinceInception

8.91%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

19.79%

5 Years

rr_AverageAnnualReturnYear05

17.83%

Since Inception

rr_AverageAnnualReturnSinceInception

7.44%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.96%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.44%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.40%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

143

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

443

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

766

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,680

XML

Document and Entity Information	0 Months Ended
	Sep. 30, 2013
Risk/Return:
Document Type	485BPOS
Document Period End Date	Sep. 30, 2013
Registrant Name	HARRIS ASSOCIATES INVESTMENT TRUST
Central Index Key	0000872323
Amendment Flag	false
Document Creation Date	Jan. 28, 2014
Document Effective Date	Jan. 28, 2014
Prospectus Date	Jan. 28, 2014
Oakmark Fund | Class I
Risk/Return:
Trading Symbol	OAKMX
Oakmark Fund | Class II
Risk/Return:
Trading Symbol	OARMX
Oakmark Select Fund | Class I
Risk/Return:
Trading Symbol	OAKLX
Oakmark Select Fund | Class II
Risk/Return:
Trading Symbol	OARLX
Oakmark Equity and Income Fund | Class I
Risk/Return:
Trading Symbol	OAKBX
Oakmark Equity and Income Fund | Class II
Risk/Return:
Trading Symbol	OARBX
Oakmark Global Fund | Class I
Risk/Return:
Trading Symbol	OAKGX
Oakmark Global Fund | Class II
Risk/Return:
Trading Symbol	OARGX
Oakmark Global Select Fund | Class I
Risk/Return:
Trading Symbol	OAKWX
Oakmark Global Select Fund | Class II
Risk/Return:
Trading Symbol	OARWX
Oakmark International Fund | Class I
Risk/Return:
Trading Symbol	OAKIX
Oakmark International Fund | Class II
Risk/Return:
Trading Symbol	OARIX
Oakmark International Small Cap Fund | Class I
Risk/Return:
Trading Symbol	OAKEX
Oakmark International Small Cap Fund | Class II
Risk/Return:
Trading Symbol	OAREX

XML

Oakmark Global Fund

Oakmark Global Fund

INVESTMENT OBJECTIVE

Oakmark Global Fund seeks long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark Global Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee	none	none
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark Global Fund	Class I	Class II
Management fees	0.97%	0.97%
Distribution (12b-1) fees	none	none
Other expenses	0.16%	0.51%
Total Annual Fund Operating Expenses	1.13%	1.48%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark Global Fund (USD $)	Class I	Class II
1 Year	115	151
3 Years	359	468
5 Years	622	808
10 Years	1,375	1,768

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 45% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

The Fund invests primarily in a diversified portfolio of common stocks of U.S. and non-U.S. companies. The Fund invests in the securities of companies located in at least three countries. Typically, the Fund invests between 25-75% of its total assets in securities of U.S. companies and between 25-75% of its total assets in securities of non-U.S. companies. There are no geographic limits on the Fund's non-U.S. investments, and the Fund may invest in securities of companies located in developed or emerging markets. The Fund may invest in the securities of large-, mid-, and small-capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular region, sector or industry.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks—thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Investments in securities issued by entities domiciled in the United States also may be subject to many of these risks. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Small and Mid Cap Securities Risk. Investments in small and mid cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, smaller companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's average annual returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 29.5%, during the quarter ended June 30, 2009
Lowest quarterly return: -24.1%, during the quarter ended December 31, 2008

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark Global Fund	1 Year	5 Years	10 Years
Class I	34.12%	18.23%	9.45%
Class II	33.67%	17.83%	9.08%
After Taxes on Distributions Class I	32.45%	17.86%	8.71%
After Taxes on Distributions and Sale of Fund Shares Class I	20.07%	14.82%	7.86%
MSCI World Index (does not reflect the deduction of fees, expenses or taxes)	26.68%	15.02%	6.98%

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Oakmark Select Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Oakmark Select Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

Below are the fees and expenses that you would pay if you buy and hold 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). A higher portfolio turnover rate 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 24% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

24.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

Example.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund invests primarily in common stocks of U.S. companies. The Fund is non-diversified, which means that it may invest a greater portion of its assets in a more limited number of issuers than a diversified fund. The Fund could own as few as twelve securities, but generally will have approximately twenty securities in its portfolio and as a result, a higher percentage of the Fund's total assets may also be invested in a particular sector or industry. The Fund generally invests in the securities of large- and mid-capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

Risk [Heading]

rr_RiskHeading

PRINCIPAL INVESTMENT RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Non-Diversification Risk. A non-diversified fund (generally, a fund that may invest in a limited number of issuers) may be subject to greater risk than a diversified fund because changes in the financial condition or market assessment of a single issuer may cause greater fluctuation in the value of a non-diversified fund's shares. The Fund could hold as few as twelve securities, but generally will have approximately twenty securities in its portfolio. Lack of broad diversification also may cause a non-diversified fund to be more susceptible to economic, political or regulatory events than a diversified fund. A non-diversification strategy may increase the Fund's volatility.

Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular sector or industry, changes affecting that sector or industry, or the perception of that sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Mid Cap Securities Risk. Investments in mid cap companies may be riskier than investments in larger, more established companies. Mid cap companies may have limited product lines, markets or financial resources or may depend on a few key employees, and may be more susceptible to particular economic events or competitive factors than large capitalization companies. The securities of mid cap companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, mid cap companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

A non-diversified fund (generally, a fund that may invest in a limited number of issuers) may be subject to greater risk than a diversified fund because changes in the financial condition or market assessment of a single issuer may cause greater fluctuation in the value of a non-diversified fund's shares. The Fund could hold as few as twelve securities, but generally will have approximately twenty securities in its portfolio. Lack of broad diversification also may cause a non-diversified fund to be more susceptible to economic, political or regulatory events than a diversified fund. A non-diversification strategy may increase the Fund's volatility.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE INFORMATION

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-800-OAKMARK

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

oakmark.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Class I Shares Total Returns for Years Ended December 31 (%)

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 25.7%, during the quarter ended June 30, 2009
Lowest quarterly return: -20.2%, during the quarter ended December 31, 2008

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest quarterly return:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

25.70%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest quarterly return:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(20.20%)

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_IndexNoDeductionForFeesExpensesTaxes

(does not reflect the deduction of fees, expenses or taxes)

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

After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Returns for Periods Ended December 31, 2013

S&P 500 Index (does not reflect the deduction of fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

32.39%

5 Years

rr_AverageAnnualReturnYear05

17.94%

10 Years

rr_AverageAnnualReturnYear10

7.41%

Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.88%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.01%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 103

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

322

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

558

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,236

Annual Return 2004

rr_AnnualReturn2004

9.73%

Annual Return 2005

rr_AnnualReturn2005

4.84%

Annual Return 2006

rr_AnnualReturn2006

13.60%

Annual Return 2007

rr_AnnualReturn2007

(14.04%)

Annual Return 2008

rr_AnnualReturn2008

(36.22%)

Annual Return 2009

rr_AnnualReturn2009

52.46%

Annual Return 2010

rr_AnnualReturn2010

13.24%

Annual Return 2011

rr_AnnualReturn2011

2.15%

Annual Return 2012

rr_AnnualReturn2012

21.74%

Annual Return 2013

rr_AnnualReturn2013

36.52%

1 Year

rr_AverageAnnualReturnYear01

36.52%

5 Years

rr_AverageAnnualReturnYear05

24.00%

10 Years

rr_AverageAnnualReturnYear10

7.70%

Class I | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

34.81%

5 Years

rr_AverageAnnualReturnYear05

23.32%

10 Years

rr_AverageAnnualReturnYear10

6.92%

Class I | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

22.02%

5 Years

rr_AverageAnnualReturnYear05

19.91%

10 Years

rr_AverageAnnualReturnYear10

6.31%

Class II

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Redemption fee

rr_RedemptionFeeOverRedemption

none

Exchange fee

rr_ExchangeFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.88%

Distribution (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.45%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.33%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

135

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

421

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

729

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,601

1 Year

rr_AverageAnnualReturnYear01

36.09%

5 Years

rr_AverageAnnualReturnYear05

23.68%

10 Years

rr_AverageAnnualReturnYear10

7.41%

XML

Oakmark Equity and Income Fund

Oakmark Equity and Income Fund

INVESTMENT OBJECTIVE

Oakmark Equity and Income Fund seeks income and preservation and growth of capital.

FEES AND EXPENSES OF THE FUND

Below are the fees and expenses that you would pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Oakmark Equity and Income Fund	Class I	Class II
Maximum sales charge (load) imposed on purchases	none	none
Maximum deferred sales charge (load)	none	none
Redemption fee	none	none
Exchange fee	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Oakmark Equity and Income Fund	Class I	Class II
Management fees	0.66%	0.66%
Distribution (12b-1) fees	none	none
Other expenses	0.11%	0.44%
Total Annual Fund Operating Expenses	0.77%	1.10%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual returns and costs may be higher or lower, based on these assumptions your expenses would be:

Expense Example Oakmark Equity and Income Fund (USD $)	Class I	Class II
1 Year	79	112
3 Years	246	350
5 Years	428	606
10 Years	954	1,340

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate 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 INVESTMENT STRATEGY

The Fund invests primarily in a diversified portfolio of U.S. equity and debt securities (although the Fund may invest up to 35% of its total assets in equity and debt securities of non-U.S. issuers). The Fund is intended to present a balanced investment program between growth and income by investing approximately 40-75% of its total assets in common stock, including securities convertible into common stock, and up to 60% of its assets in U.S. government securities and debt securities, including inflation-indexed securities, rated at time of purchase within the two highest grades assigned by Moody's Investors Service, Inc. or by Standard & Poor's Corporation Ratings Group, a division of The McGraw-Hill Companies. The Fund also may invest up to 20% of its total assets in unrated or below investment grade rated debt securities, sometimes called junk bonds. The types of equity securities in which the Fund may invest include common and preferred stocks and warrants or other similar rights and convertible securities. The types of debt securities in which the Fund may invest include debt securities of both governmental and corporate issuers. The Fund may invest in the securities of large-, mid-, and small-capitalization companies.

The Fund uses a value investment philosophy in selecting equity securities. This investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic or true business value. By "true business value," we mean an estimate of the price a knowledgeable buyer would pay to acquire the entire business. We believe that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objective.

The Fund's investment adviser, Harris Associates L.P. (the "Adviser"), uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, the Adviser looks for the following characteristics, although not all of the companies selected will have all of these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Key Tenets of the Oakmark Investment Philosophy—Equity Portion of the Fund:

1.  Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.

2.  Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason—because the company just does not grow. The Adviser looks for good quality, growing businesses with positive free cash flow and intelligent investment of cash.

3.  Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its equity investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. In order to select investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser determines that a stock is selling at a significant discount and that the company has the additional qualities mentioned above, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated worth. This means the Adviser sets specific "buy" and "sell" targets for each stock held by the Fund. The Adviser also monitors each holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of stocks allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds thirty to sixty stocks rather than hundreds, and a higher percentage of the Fund's total assets may also be invested in a particular sector or industry.

The proportion of the Fund held in debt securities will vary in light of the Adviser's view of the attractiveness of debt securities. In times when the Adviser believes equities provide above average absolute value, the proportion of the Fund allocated to fixed income will decline. In selecting debt securities, the Adviser considers many factors, including among other things, quality, yield-to-maturity, liquidity, current yield and call risk. The Adviser believes the role of fixed income investments in the Fund is to help buffer the volatility of the Fund's equity portfolio and generate income.

PRINCIPAL INVESTMENT RISKS

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the U.S. or abroad. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Although the Fund makes every effort to achieve its objective, it cannot guarantee it will attain that objective. The principal risks of investing in the Fund are:

Market Risk. The Fund is subject to market risk—the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to market or economic news and conditions, and securities markets also tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade.

Common Stock Risk. Common stocks are subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of common stockholders are subordinate to all other claims on a company's assets including debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' true business values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform growth stocks during given periods.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of stocks—thirty to sixty rather than hundreds. As a result, the appreciation or depreciation of any one security held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of securities. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility.

Small and Mid Cap Securities Risk. Investments in small and mid cap companies may be riskier than investments in larger, more established companies. The securities of smaller companies may trade less frequently and in smaller volumes, and as a result, may be less liquid than securities of larger companies. In addition, smaller companies may be more vulnerable to economic, market and industry changes. As a result, share price changes may be more sudden or erratic than the prices of other equity securities, especially over the short term. Because smaller companies may have limited product lines, markets or financial resources or may depend on a few key employees, they may be more susceptible to particular economic events or competitive factors than large capitalization companies.

Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular sector or industry, changes affecting that sector or industry, or the perception of that sector or industry, may have a significant impact on the performance of the Fund's overall portfolio.

Debt Securities Risk. Debt securities are subject to credit risk, interest rate risk and liquidity risk. Credit risk is the risk the issuer or guarantor of a debt security will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. Interest rate risk is the risk of losses due to changes in interest rates. In general, the prices of debt securities rise when interest rates fall, and the prices fall when interest rates rise. Liquidity risk is the risk a particular security may be difficult to purchase or sell and that the Fund may be unable to sell such security at an advantageous time or price. The Fund's investments in government-sponsored entity securities also exhibit these risks, although the degree of such risks may vary significantly among the different government-sponsored entity securities. Some securities issued or guaranteed by U.S. government agencies or instrumentalities are not backed by the full faith and credit of the U.S. and may only be supported by the right of the agency or instrumentality to borrow from the U.S. Treasury. There can be no assurance that the U.S. government will always provide financial support to those agencies or instrumentalities. Sovereign debt instruments, including U.S. and non-U.S. debt instruments, are subject to the risk that a governmental entity may delay, refuse, or be unable to pay interest or repay principal on its debt. There is no legal process for collecting sovereign debt that a government does not pay, nor are there bankruptcy proceedings through which all or part of the sovereign debt that a government entity has not repaid may be collected. Below investment grade securities (commonly referred to as junk bonds) are regarded as having predominately speculative characteristics and may be more susceptible to credit, interest rate or liquidity risk than a debt security rated investment grade.

Inflation-Indexed Securities Risk. The principal value of an investment by the Fund is not protected or otherwise guaranteed by virtue of the Fund's investments in inflation-indexed bonds. If the index measuring inflation falls, the principal value of inflation-indexed bonds will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced.

Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds. For bonds that do not provide a similar guarantee, the adjusted principal value of the bond repaid at maturity may be less than the original principal value.

The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates are tied to the relationship between nominal interest rates and the rate of inflation. If nominal interest rates increase at a faster rate than inflation, real interest rates may rise, leading to a decrease in value of inflation indexed bonds. Short-term increases in inflation may lead to a decline in value. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

Periodic adjustments for inflation to the principal amount of an inflation-indexed bond may give rise to original issue discount, which will be includable in the Fund's gross income. Due to original issue discount, the Fund may be required to make annual distributions to shareholders that exceed the cash received, which may cause the Fund to liquidate certain investments when it is not advantageous to do so. Also, if the principal value of an inflation-indexed bond is adjusted downward due to deflation, amounts previously distributed in the taxable year may be characterized in some circumstances as a return of capital.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may result in the Fund experiencing rapid and extreme value changes due to currency controls; different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Investments in securities issued by entities domiciled in the United States also may be subject to many of these risks.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

PERFORMANCE INFORMATION

The Fund's past performance (before and after taxes), as provided by the bar chart and performance table that follow, is not an indication of how the Fund will perform in the future. This information can help you evaluate the potential risk and reward of investing in the Fund by showing changes in the performance of the Fund's Class I Shares from year to year. The information illustrates the volatility of the Fund's historical returns and shows how the Fund's annual average returns compare with those of a broad measure of market performance. Updated performance information is available at oakmark.com or by calling 1-800-OAKMARK.

Class I Shares Total Returns for Years Ended December 31 (%)

Since 2004, the highest and lowest quarterly returns for the Fund's Class I Shares were:
Highest quarterly return: 10.6%, during the quarter ended September 30, 2009
Lowest quarterly return: -12.8%, during the quarter ended September 30, 2011

Average Annual Total Returns for Periods Ended December 31, 2013

Average Annual Returns Oakmark Equity and Income Fund	1 Year	5 Years	10 Years
Class I	24.25%	12.34%	8.35%
Class II	23.83%	11.98%	8.02%
After Taxes on Distributions Class I	21.94%	11.62%	7.54%
After Taxes on Distributions and Sale of Fund Shares Class I	15.56%	9.93%	6.79%
Lipper Balanced Funds Index (does not reflect the deduction of fees, expenses or taxes)	16.39%	12.62%	6.19%
S&P 500 Index (does not reflect the deduction of fees, expenses or taxes)	32.39%	17.94%	7.41%
Barclays U.S. Government/Credit Index (does not reflect the deduction of fees, expenses or taxes)	(2.36%)	4.40%	4.52%

Lipper Balanced Funds Index is an index of the thirty largest balanced funds tracked by Lipper, Inc. All returns reflect reinvested dividends. This information shows how the Fund's returns compare with the returns of an index comprised of the thirty largest balanced funds tracked by Lipper, Inc.

The S&P 500 Index is a widely quoted, unmanaged, market weighted index that includes 500 of the largest publicly traded companies in the U.S. All returns reflect reinvested dividends. This information shows how the Fund's returns compare with a broad-based securities market index.

The Barclays U.S. Government & Credit Index measures the performance of U.S. dollar-denominated U.S. Treasury bonds, government-related bonds and investment grade U.S. corporate bonds that have a remaining maturity of greater than or equal to one year. This information shows how the Fund's returns compare with a broad-based securities market index.

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 an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts or individual retirement accounts. In some cases, the after-tax returns may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are shown only for Class I shares. After-tax returns for Class II shares will vary from returns shown for Class I.

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Prospectus Date	rr_ProspectusDate	Jan. 28, 2014