Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Aug. 01, 2017
iShares U.S. Oil & Gas Exploration & Production ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® U.S. OIL & GAS EXPLORATION & PRODUCTION ETF Ticker: IEO                                 Stock Exchange: NYSE Arca
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares U.S. Oil & Gas Exploration & Production ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. equities in the oil and gas exploration and production sector.
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 the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. You may also incur usual and customary brokerage commissions and other charges 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 8% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	8.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions and other charges 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 Fund seeks to track the investment results of the Dow Jones U.S. Select Oil Exploration & Production Index (the "Underlying Index"), which measures the performance of the oil exploration and production sector of the U.S. equity market, as determined by S&P Dow Jones Indices LLC (the "Index Provider" or "SPDJI"). The Underlying Index includes companies that are engaged in the exploration for and drilling, production, refining, and supply of oil and gas products. The Underlying Index may include large-, mid- or small-capitalization companies. As of March 31, 2017, a significant portion of the Underlying Index is represented by securities of energy and oil and gas companies. The components of the Underlying Index are likely to change over time. 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 that of 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 and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities in an applicable underlying index. The Fund generally invests at least 90% of its assets in securities of the Underlying Index and in depositary receipts representing securities of the Underlying Index. The Fund may invest the remainder of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of any collateral received). The Underlying Index is sponsored by SPDJI which 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. 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 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) and repurchase agreements collateralized by U.S. government securities 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 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) and repurchase agreements collateralized by U.S. government securities 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 certain risks, including 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 and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of this prospectus (the "Prospectus")), a third-party investor, the Fund's adviser or an affiliate of the Fund's adviser, or a fund may invest in the Fund and hold its investment for a specific period of time in order to facilitate commencement of the Fund's operations or for the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts and/or delisting. Concentration Risk. The Fund may be susceptible to an increased risk of loss, including losses due to adverse events that affect the Fund's investments more than the market as a whole, to the extent that the Fund's investments are concentrated in the securities of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Cyber Security Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions and negatively impact the Fund's business operations, potentially resulting in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cyber security plans and systems of the Fund's service providers, the Index Provider, market makers, Authorized Participants or issuers of securities in which the Fund invests. Energy Sector Risk. The market value of securities issued by companies in the energy sector may decline for many reasons, including, among others, changes in energy prices, energy supply and demand, and government regulations, energy conservation efforts and potential civil liabilities. Equity Securities Risk. Equity securities are subject to changes in value, and their values may be more volatile than those of other asset classes. The Underlying Index is comprised of common stocks, which generally subject their holders to more risks than holders of preferred stock and debt securities because common stockholders' claims are subordinated to holders of preferred stock and debt securities upon the bankruptcy of the issuer. Index-Related Risk. There is no guarantee that the Fund will achieve a high degree of correlation to the Underlying Index and therefore achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund's ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations and/or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. Changes in the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Large-Capitalization Companies Risk. Large-capitalization companies may be less able than smaller capitalization companies to adapt to changing market conditions. Large-capitalization companies may be more mature and subject to more limited growth potential compared with smaller capitalization companies. During different market cycles, the performance of large-capitalization companies has trailed the overall performance of the broader securities markets. Management Risk. As the Fund may not fully replicate the Underlying Index, it is subject to the risk that BFA's investment 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 more prolonged 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 disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Mid-Capitalization Companies Risk. Compared to large-capitalization companies, mid-capitalization companies may be less stable and more susceptible to adverse developments, and their securities may be more volatile and less liquid. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. Oil and Gas Industry Risk. Companies in the oil and gas industry are affected by worldwide energy prices and exploration and production costs. Companies in the oil and gas industry may have significant operations in areas at risk for natural disasters, social and political unrest, and environmental damage. These companies may also be at risk for increased government regulation and intervention, litigation, and negative publicity and public perception. Operational Risk. The Fund is exposed to operational risks arising from a number of factors, including, but not limited to, human error, processing and communication errors, errors of the Fund's service providers, counterparties or other third-parties, failed or inadequate processes and technology or systems failures. The Fund and BFA seek to reduce these operational risks through controls and procedures. However, these measures do not address every possible risk and may be inadequate to address these risks. Passive Investment Risk. The Fund is not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Risk of Investing in the United States. The Fund has significant exposure to U.S. issuers. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. 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 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 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. Tracking Error Risk. Tracking error is the divergence of a fund's performance from that of the applicable underlying index. Tracking error may occur because of differences between the securities and other instruments held in a fund's portfolio and those included in the applicable underlying index, pricing differences, differences in transaction costs, the fund's holding of uninvested cash, differences in timing of the accrual of or the valuation of dividends or interest, tax gains or losses, changes to the applicable underlying index or the costs to the fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because a fund incurs fees and expenses, while the applicable underlying index does not.
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.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
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 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 24.97% in the 2nd quarter of 2008; the worst was -34.84% in the 3rd 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, 2016)
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 sales 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 sales of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.
iShares U.S. Oil & Gas Exploration & Production ETF | iShares U.S. Oil & Gas Exploration & Production ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.44%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.44%
1 Year	rr_ExpenseExampleYear01	$ 45
3 Years	rr_ExpenseExampleYear03	141
5 Years	rr_ExpenseExampleYear05	246
10 Years	rr_ExpenseExampleYear10	$ 555
2007	rr_AnnualReturn2007	39.71%
2008	rr_AnnualReturn2008	(41.95%)
2009	rr_AnnualReturn2009	40.67%
2010	rr_AnnualReturn2010	18.97%
2011	rr_AnnualReturn2011	(3.26%)
2012	rr_AnnualReturn2012	4.37%
2013	rr_AnnualReturn2013	30.63%
2014	rr_AnnualReturn2014	(12.27%)
2015	rr_AnnualReturn2015	(24.60%)
2016	rr_AnnualReturn2016	25.09%	[1]
Year to Date Return, Label	rr_YearToDateReturnLabel	The Fund's year-to-date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Jun. 30, 2017
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	(16.02%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	best
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2008
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	24.97%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	worst
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(34.84%)
One Year	rr_AverageAnnualReturnYear01	25.09%
Five Years	rr_AverageAnnualReturnYear05	2.44%
Ten Years	rr_AverageAnnualReturnYear10	4.01%
Inception Date	rr_AverageAnnualReturnInceptionDate	May 01, 2006
iShares U.S. Oil & Gas Exploration & Production ETF | Return After Taxes on Distributions | iShares U.S. Oil & Gas Exploration & Production ETF
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	24.76%	[2]
Five Years	rr_AverageAnnualReturnYear05	2.18%	[2]
Ten Years	rr_AverageAnnualReturnYear10	3.84%	[2]
iShares U.S. Oil & Gas Exploration & Production ETF | Return After Taxes on Distributions and Sale of Fund Shares | iShares U.S. Oil & Gas Exploration & Production ETF
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	14.42%	[2]
Five Years	rr_AverageAnnualReturnYear05	1.89%	[2]
Ten Years	rr_AverageAnnualReturnYear10	3.19%	[2]
iShares U.S. Oil & Gas Exploration & Production ETF | Dow Jones U.S. Select Oil Exploration & Production Index (Index returns do not reflect deductions for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	25.84%
Five Years	rr_AverageAnnualReturnYear05	2.85%
Ten Years	rr_AverageAnnualReturnYear10	4.44%

[1] The Fund's year-to-date return as of June 30, 2017 was -16.02%.

[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 sales 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 sales of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.