Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Jul. 01, 2012
iShares iBoxx $ High Yield Corporate Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® iBOXX $ HIGH YIELD CORPORATE BOND FUND Ticker: HYG   Stock Exchange: NYSE Arca
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares iBoxx $ High Yield Corporate Bond Fund (the “Fund”) seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Markit iBoxx® USD Liquid High Yield Index (the “Underlying Index”).
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except interest expenses, taxes, brokerage expenses, future distribution fees or expenses, and extraordinary expenses. You may also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover.
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund may pay 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 13% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	13.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the example that follows:
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell 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 costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Underlying Index is a rules-based index consisting of liquid U.S. dollar-denominated, high yield corporate bonds for sale in the United States, as determined by the index provider. The Underlying Index is designed to provide a broad representation of the U.S. dollar-denominated liquid high yield corporate bond market. The Underlying Index is a modified market-value weighted index with a cap on each issuer of 3%. Bonds in the Underlying Index are selected using a rules-based criteria, as defined by the index provider. There is no limit to the number of issues in the Underlying Index, but as of April 30, 2012, the Underlying Index included approximately 639 constituents. Components primarily include consumer services, financial, industrials, oil and gas, and telecommunications entities, and may change over time. Currently, the bonds eligible for inclusion in the Underlying Index include U.S. dollar-denominated high yield corporate bonds that: (i) are issued by companies domiciled in countries classified as developed markets by the index provider; (ii) are rated sub-investment grade by Fitch, Inc. (“Fitch”), Moody’s Investors Services (“Moody’s”) or Standard & Poor’s Ratings Services; (iii) are from issuers with at least $1 billion outstanding face value; (iv) have at least $400 million of outstanding face value; (v) have an original maturity date of less than 15 years; and (vi) have at least one year to maturity. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability, duration, maturity or credit ratings and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities in the Underlying Index. The Fund generally invests at least 90% of its assets in the securities of the Underlying Index and in investments that provide substantially similar exposure to the securities in the Underlying Index. However, the Fund may at times invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including money market funds advised by BFA or its affiliates, as well as in bonds not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received). The Underlying Index is sponsored by an organization (the “Index Provider”) that is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. The Fund’s Index Provider is Markit Indices Limited (“Markit”). Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries, which may include large-, mid- or small-capitalization companies, to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry.
Strategy Portfolio Concentration [Text]	rr_StrategyPortfolioConcentration	Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries, which may include large-, mid- or small-capitalization companies, to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry.
Risk [Heading]	rr_RiskHeading	Summary of Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to the principal risks noted below, any of which may adversely affect the Fund’s net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. Asset Class Risk. Securities in the Underlying Index or in the Fund’s portfolio may underperform in comparison to the general securities markets or other asset classes. Call Risk. During periods of falling interest rates, an issuer of a callable bond held by the Fund may “call” or repay the security before its stated maturity, and the Fund may have to reinvest the proceeds at lower interest rates, resulting in a decline in the Fund’s income. Concentration Risk. To the extent that the Fund’s investments are concentrated in a particular region, country, market, industry or asset class, the Fund may be susceptible to loss due to adverse occurrences affecting that region, country, market, industry or asset class. Consumer Services Sector Risk. The consumer services sector may be affected by changes in the domestic and international economy, exchange rates, competition, consumers’ disposable income and consumer preferences. Credit Risk. The Fund is subject to the risk that debt issuers and other counterparties may not honor their obligations or may have their debt downgraded by ratings agencies. Extension Risk. During periods of rising interest rates, certain obligations will be paid off substantially more slowly than originally anticipated and the value of those securities may fall sharply, resulting in a decline to the Fund’s income and potentially in the value of the Fund’s investments. Financial Sector Risk. Performance of companies in the financial sector may be adversely impacted by many factors, including, among others, government regulations, economic conditions, credit rating downgrades, changes in interest rates, and decreased liquidity in credit markets. This sector has experienced significant losses in the recent past, and the impact of more stringent capital requirements and of recent or future regulation on any individual financial company or on the sector as a whole cannot be predicted. High Yield Securities Risk. Securities that are rated below investment grade (commonly referred to as “junk bonds,” including those bonds rated lower than “BBB-” by S&P and Fitch, or “Baa3” by Moody’s), or are unrated, may be deemed speculative and more volatile than higher-rated securities of similar maturity. Income Risk. The Fund’s income may decline when interest rates fall. This decline can occur because the Fund must invest in lower-yielding bonds as bonds in its portfolio mature, bonds in the Underlying Index are substituted or the Fund otherwise needs to purchase additional bonds. Industrials Sector Risk. The industrials sector may be affected by changes in the supply and demand for products and services, product obsolescence, claims for environmental damage or product liability and general economic conditions, among other factors. Interest Rate Risk. An increase in interest rates may cause the value of fixed-income securities held by the Fund to decline. Issuer Risk. Fund performance depends on the performance of individual securities to which the Fund has exposure. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Liquidity Risk. Liquidity risk exists when particular investments are difficult to purchase or sell. This can reduce the Fund’s returns because the Fund may be unable to transact at advantageous times or prices. Management Risk. As the Fund may not fully replicate the Underlying Index, it is subject to the risk that BFA’s investment management strategy may not produce the intended results. Market Risk. The Fund could lose money over short periods due to short-term market movements and over longer periods during market downturns. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation/redemption process of the Fund. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-U.S. Issuers Risk. Securities issued by non-U.S. issuers carry different risks from securities issued by U.S. issuers. These include differences in accounting, auditing and financial reporting standards, the possibility of expropriation or confiscatory taxation, adverse changes in investment or exchange control regulations, political instability, regulatory and economic differences, and potential restrictions on the flow of international capital. The Fund is specifically exposed to North American Economic Risk. Oil and Gas Sector Risk. Companies in the oil and gas sector are affected by worldwide energy prices and exploration and production costs. Companies in the oil and gas sector may have significant operations in areas at risk for natural disasters, social unrest and environmental damage. These companies may also be at risk for increased government regulation and intervention, litigation, and negative publicity and perception. Passive Investment Risk. The Fund is not actively managed and BFA does not attempt to take defensive positions under any market conditions, including declining markets. Privately-Issued Securities Risk. The Fund may invest in privately-issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the Securities Act of 1933, as amended (the “1933 Act”). Privately-issued securities are securities that have not been registered under the 1933 Act and as a result are subject to legal restrictions on resale. Privately-issued securities are not traded on established markets and may be illiquid, difficult to value and subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Securities Lending Risk. The Fund may engage in securities lending. Securities lending involves the risk that the Fund may lose money because the borrower of the Fund’s loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money in the event of a decline in the value of the collateral provided for loaned securities or a decline in the value of any investments made with cash collateral. These events could also trigger adverse tax consequences for the Fund. Telecommunications Sector Risk. Companies in the telecommunications sector may be affected by industry competition, substantial capital requirements, government regulation and obsolescence of telecommunications products and services due to technological advancement. Tracking Error Risk. Tracking error is the divergence of the Fund’s performance from that of the Underlying Index. Tracking error may occur because of imperfect correlation between the Fund’s holdings of portfolio securities and those in the Underlying Index, pricing differences, the Fund’s holding of cash, differences on timing of the accrual of dividends, changes to the Underlying Index or the need to meet various regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. BFA expects that the Fund may experience higher tracking error than is typical for similar index ETFs.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund. Both assume that all dividends and distributions have been reinvested in the Fund. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Supplemental information about the Fund’s performance is shown under the heading Total Return Information in the Supplemental Information section of the Fund’s prospectus (the “Prospectus”).
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-iShares (1-800-474-2737) (toll free)
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.iShares.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Year by Year Returns (Years Ended December 31)
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	The best calendar quarter return during the periods shown above was 17.05% in the 2nd quarter of 2009; the worst was -15.51% in the 4th quarter of 2008. Updated performance information is available at www.iShares.com or by calling 1-800-iShares (1-800-474-2737) (toll free).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns in the table above are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and after-tax returns shown are not relevant to tax-exempt investors or investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”).
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Fund returns after taxes on distributions and sale of Fund shares are calculated assuming that an investor has sufficient capital gains of the same character from other investments to offset any capital losses from the sale of Fund shares. As a result, Fund returns after taxes on distributions and sale of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.
iShares iBoxx $ High Yield Corporate Bond Fund | iShares iBoxx $ High Yield Corporate Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.50%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.50%
1 Year	rr_ExpenseExampleYear01	51
3 Years	rr_ExpenseExampleYear03	160
5 Years	rr_ExpenseExampleYear05	280
10 Years	rr_ExpenseExampleYear10	628
2008	rr_AnnualReturn2008	(23.89%)	[1]
2009	rr_AnnualReturn2009	40.68%	[1]
2010	rr_AnnualReturn2010	12.07%	[1]
2011	rr_AnnualReturn2011	5.89%	[1]
Year to Date Return, Label	rr_YearToDateReturnLabel	The Fund's total return for the three months ended
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Mar. 31, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	4.49%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	best
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	17.05%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	worst
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(15.51%)
One Year	rr_AverageAnnualReturnYear01	5.89%
Since Fund Inception	rr_AverageAnnualReturnSinceInception	5.36%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 04, 2007
iShares iBoxx $ High Yield Corporate Bond Fund | Return After Taxes on Distributions | iShares iBoxx $ High Yield Corporate Bond Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	3.13%	[2]
Since Fund Inception	rr_AverageAnnualReturnSinceInception	2.21%	[2]
iShares iBoxx $ High Yield Corporate Bond Fund | Return After Taxes on Distributions and Sale of Fund Shares | iShares iBoxx $ High Yield Corporate Bond Fund
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	3.79%	[2]
Since Fund Inception	rr_AverageAnnualReturnSinceInception	2.63%	[2]
iShares iBoxx $ High Yield Corporate Bond Fund | Markit iBoxx® USD Liquid High Yield Index (Index returns do not reflect deductions for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	5.94%
Since Fund Inception	rr_AverageAnnualReturnSinceInception	5.88%

[1] The Fund's total return for the three months ended March 31, 2012 was 4.49%.

[2] After-tax returns in the table above are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state or local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to tax-exempt investors or investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts ("IRAs"). Fund returns after taxes on distributions and sale of Fund shares are calculated assuming that an investor has sufficient capital gains of the same character from other investments to offset any capital losses from the sale of Fund shares. As a result, Fund returns after taxes on distributions and sale of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.