Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Jun. 08, 2020
iShares ESG Aware Aggressive Allocation ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iShares ESG Aware Aggressive Allocation ETF Ticker: EAOA Stock Exchange: Cboe BZX
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares ESG Aware Aggressive Allocation ETF (the “Fund”) seeks to track the investment results of an index composed of a portfolio of underlying equity and fixed income funds with positive environmental, social, and governance characteristics intended to represent an aggressive risk profile.
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. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”). BFA, the investment adviser to the Fund, has contractually agreed to waive a portion of its management fees in an amount equal to the Acquired Fund Fees and Expenses, if any, attributable to investments by the Fund in other series of the Trust and iShares, Inc. through November 30, 2025. The contractual waiver may be terminated prior to November 30, 2025 only upon written agreement of the Trust and BFA. 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)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	November 30, 2025
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover.
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund and the iShares funds in which the Fund invests (each, an “Underlying Fund” and collectively, the “Underlying Funds”), may pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolio). A higher portfolio turnover rate for the Fund or Underlying Funds may indicate higher transaction costs and may cause the Fund or Underlying Funds to incur increased expenses. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example (except costs to Underlying Funds included as part of Acquired Fund Fees and Expenses), affect the Fund’s performance. To the extent an Underlying Fund incurs costs from high portfolio turnover, such costs may have a negative effect on the performance of the Fund.
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:
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).
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 is a fund of funds and seeks to achieve its investment objective by investing primarily in Underlying Funds that themselves seek investment results corresponding to their own respective underlying indexes each of which takes into account ESG characteristics. The Underlying Funds invest primarily in companies or issuers that exhibit positive ESG characteristics, as identified by the index provider of each Underlying Fund in distinct asset classes, such as large-, mid- or small-capitalization U.S. or non-U.S. equity, and the broad U.S. dollar-denominated investment-grade bond market; each such asset class has its own risk profile. The BlackRock ESG Aware Aggressive Allocation Index (the “Underlying Index”) is composed of a portfolio of ESG-oriented equity and fixed income Underlying Funds and measures the performance of BIS’s fixed allocation strategy that is intended to represent an “aggressive” risk profile with an 80% allocation to equities and 20% allocation to fixed income, as defined by BIS. BIS’s estimation of an aggressive risk profile may differ from your own. The Underlying Index is rebalanced semi-annually after the market close on the last business day of April and October. At each rebalancing, the Fund will adjust its portfolio to align with the 20% allocation to fixed income and 80% allocation to equity prescribed by the Index Provider. The Fund's allocation to fixed income and equity may fluctuate due to appreciation or depreciation in the market value of the Fund's assets. At each rebalance, the Underlying Index will include a fixed allocation of 80% of its assets in Underlying Funds that invest primarily in equity securities and 20% of its assets in Underlying Funds that invest primarily in U.S. dollar-denominated investment-grade bonds. As of May 11, 2020, the Underlying Index was comprised of approximately 80.94% of its assets in Underlying Funds that invest primarily in equity securities and 19.06% of its assets in Underlying Funds that invest primarily in U.S. dollar-denominated investment-grade bonds. As of May 11, 2020, the Underlying Index was comprised of the iShares ESG MSCI USA ETF, iShares ESG MSCI USA Small-Cap ETF, iShares ESG MSCI EAFE ETF, iShares ESG MSCI EM ETF, and iShares ESG U.S. Aggregate Bond ETF. As of May 11, 2020, a significant portion of the Underlying Index is represented by securities of companies in the information technology industry or sector. The components of the Underlying Index are unlikely 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 aiming to keep 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 an applicable 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 an applicable underlying index. The Fund and an Underlying Fund may or may not hold all of the securities in the applicable Underlying Index. The Fund will invest at least 80% of its assets, exclusive of collateral held from securities lending, in the component securities of the Underlying Index and may invest up to 20% of its assets in certain index futures, options, options on index futures, swap contracts or other derivatives, as related to its Underlying Index and its component securities, cash and cash equivalents, other investment companies, as well as in securities and other instruments 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 the Index Provider, an affiliated person of the Fund and of BFA, the Fund's investment adviser. 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 (either directly or through its investments in the Underlying Funds), 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. The order of the below risk factors does not indicate the significance of any particular risk factor. Affiliated Fund Risk. In managing the Fund, BFA will have the ability to select Underlying Funds and substitute Underlying Funds with other exchange-traded funds (“ETFs”) that it believes will achieve the Fund’s objective. BFA may be subject to potential conflicts of interest in selecting Underlying Funds and substituting Underlying Funds with other ETFs because the fees paid to BFA by some Underlying Funds and other ETFs managed by BFA may be higher than the fees paid by other Underlying Funds. If an Underlying Fund or other ETF holds interests in an affiliated fund in excess of a certain amount, the Fund may be prohibited from purchasing shares of that Underlying Fund or other ETF. Allocation Risk. The Fund’s ability to achieve its investment objective depends upon the Index Provider's ability to develop a model that accurately assesses the Fund’s asset class allocation and selects the best mix of Underlying Funds and other ETFs. There is a risk that the Index Provider's evaluations and assumptions regarding asset classes or Underlying Funds, which are utilized as inputs in the model, may be incorrect in view of actual market conditions. Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's or an Underlying 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), 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 to allow 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 (as defined in the Creations and Redemptions section of this prospectus (the “Prospectus”)) may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. 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 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 or delisting. Authorized Participant concentration risk may be heightened for ETFs, such as the Fund, that invest in securities issued by non-U.S. issuers or other securities or instruments that have lower trading volumes. Calculation Methodology Risk. The Underlying Index relies on various sources of information to assess the criteria of issuers included in the Underlying Index, including information that may be based on assumptions and estimates. Neither the Fund nor BFA can offer assurances that the Underlying Index’s calculation methodology or sources of information will provide an accurate assessment of included issuers. 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 or an Underlying Fund's investments are concentrated in the securities and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Credit Risk. Debt issuers and other counterparties may be unable or unwilling to make timely interest and/or principal payments when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s or an Underlying Fund's investment in that issuer. The degree of credit risk depends on an issuer's or counterparty's financial condition and on the terms of an obligation. Currency Risk. Because the Fund's and the Underlying Funds' NAVs are determined in U.S. dollars, the Fund's NAV could decline if a currency of a non-U.S. market in which a Fund or an Underlying Fund invests depreciates against the U.S. dollar or if there are delays or limits on repatriation of such currency. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the Fund's NAV may change quickly and without warning. Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund or the Underlying Funds, the Funds' or the Underlying Funds' adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result 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 cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests. Derivatives Risk. The Fund or an Underlying Fund may invest in certain types of derivatives contracts, including futures, options and swaps, which can be more sensitive to changes in interest rates or to sudden fluctuations in market prices than conventional securities, which can result in greater losses to the Fund. Equity Securities Risk. Equity securities are subject to changes in value, and their values may be more volatile than those of other asset classes. Certain Underlying Funds invest in common stocks, which generally subject their holders to more risks than preferred stocks and debt securities because common stockholders’ claims are subordinated to those of holders of preferred stocks and debt securities upon the bankruptcy of the issuer. ESG Investment Strategy Risk. The Fund’s ESG investment strategy limits the types and number of investment opportunities available to the Fund and, as a result, the Fund may underperform other funds that do not have an ESG focus. The Fund’s ESG investment strategy may result in the Fund investing in securities or industry sectors that underperform the market as a whole or underperform other funds screened for ESG standards. In addition, companies selected by the Index Provider may not exhibit positive or favorable ESG characteristics. Geographic Risk. A natural disaster could occur in a geographic region in which the Fund or an Underlying Fund invests, which could adversely affect the economy or the business operations of companies in the specific geographic region, causing an adverse impact on the Fund's or an Underlying Fund's investments in, or which are exposed to, the affected region. High Portfolio Turnover Risk. High portfolio turnover (considered by the Fund and the Underlying Funds to mean higher than 100% annually) may result in increased transaction costs to the Fund or an Underlying Fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities. Income Risk. The Fund's income may decline if interest rates fall. This decline in income can occur because the Fund or an Underlying Fund may subsequently invest in lower-yielding bonds when bonds in its portfolio mature, are near maturity or are called, bonds in the Underlying Index are substituted, or the Fund or an Underlying Fund otherwise needs to purchase additional bonds. Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will 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 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. Because the Underlying Index is a new index and the Index Provider is also new to creation of securities indexes, there may be a greater risk that index errors will not be detected as quickly as they might be in the case of an index that has been maintained over time by a long-standing index provider. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts. Information Technology Sector Risk. Information technology companies face intense competition and potentially rapid product obsolescence. They are also heavily dependent on intellectual property rights and may be adversely affected by the loss or impairment of those rights. Companies in the information technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action. Companies in the software industry may be adversely affected by, among other things, the decline or fluctuation of subscription renewal rates for their products and services and actual or perceived vulnerabilities in their products or services. Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates. Investment in Underlying Funds Risk. The Fund invests substantially all of its assets in the Underlying Funds, so the Fund’s investment performance is directly related to the performance of the Underlying Funds. The Fund’s NAV will change with changes in the value of the Underlying Funds and other securities in which the Fund invests based on their market valuations. An investment in the Fund will entail more costs and expenses than a direct investment in the Underlying Funds. As the Underlying Funds, or the Fund’s allocations among the Underlying Funds, change from time to time, or to the extent that the total annual fund operating expenses of any Underlying Fund changes, the weighted average operating expenses borne by the Fund may increase or decrease. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund or an Underlying 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 or the Underlying Funds will not fully replicate their respective indexes, they are subject to the risk that BFA's investment strategy may not produce the intended results. Market Risk. The Fund and the Underlying Funds could lose money over short periods due to short-term market movements and over longer periods during more prolonged market downturns. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV. Market Trading Risk. The Fund and the Underlying Funds face numerous market trading risks, including the potential lack of an active market for their 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. Model Risk. Neither the Fund nor BFA can offer assurances that the Underlying Index's allocation model will achieve its intended results or maximize returns or minimize risk, or be appropriate for every investor seeking a particular risk profile. National Closed Market Trading Risk. To the extent that the underlying securities and/or other assets held by the Fund or the Underlying Funds trade on foreign exchanges or in foreign markets that may be closed when the securities exchange on which the Fund’s or an Underlying Fund's shares trade is open, there are likely to be deviations between the current price of such an underlying security and the last quoted price for the underlying security (i.e., the Fund’s or an Underlying Fund's quote from the closed foreign market). These deviations could result in premiums or discounts to the Fund’s or an Underlying Fund's NAV that may be greater than those experienced by other ETFs. Non-U.S. Issuers Risk. Securities issued by non-U.S. issuers carry different risks from securities issued by U.S. issuers. These risks 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. Non-U.S. Securities Risk. Investments in the securities of non-U.S. issuers are subject to the risks associated with investing in those non-U.S. markets, such as heightened risks of inflation or nationalization. The Fund or an Underlying Fund may lose money due to political, economic and geographic events affecting issuers of non-U.S. securities or non-U.S. markets. In addition, non-U.S. securities markets may trade a small number of securities and may be unable to respond effectively to changes in trading volume, potentially making prompt liquidation of holdings difficult or impossible at times. The Fund is specifically exposed to European Economic Risk. Operational Risk. The Fund and the Underlying Funds are 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, the Underlying Funds 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 significant operational risks. Passive Investment Risk. The Fund and the Underlying Funds are not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Prepayment Risk. During periods of falling interest rates, issuers of certain debt obligations may repay principal prior to the security’s maturity, which may cause the Fund and the Underlying Funds to have to reinvest in securities with lower yields or higher risk of default, resulting in a decline in the Fund’s income or return potential. Privately Issued Securities Risk. The Fund or the Underlying Funds 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 may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Reinvestment Risk. The Fund or an Underlying Fund may invest a portion of its assets in short-term fixed-income instruments and, as a result, may be adversely affected if interest rates fall because they may have to invest in lower-yielding bonds as bonds mature. Reliance on Trading Partners Risk. The Fund and certain Underlying Funds invest in countries or regions whose economies are heavily dependent upon trading with key partners. Any reduction in this trading may have an adverse impact on the Fund's investments. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk, European Economic Risk and U.S. Economic Risk. Risk of Investing in Developed Countries. The Fund’s or an Underlying Fund's investment in developed country issuers may subject the Fund to regulatory, political, currency, security, economic and other risks associated with developed countries. Developed countries tend to represent a significant portion of the global economy and have generally experienced slower economic growth than some less developed countries. Certain developed countries have experienced security concerns, such as terrorism and strained international relations. Incidents involving a country’s or region’s security may cause uncertainty in its markets and may adversely affect its economy and the Fund’s or an Underlying Fund's investments. In addition, developed countries may be adversely impacted by changes to the economic conditions of certain key trading partners, regulatory burdens, debt burdens and the price or availability of certain commodities. Risk of Investing in the U.S. 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 or the Underlying Funds has exposure. Securities Lending Risk. The Fund or an Underlying Fund may engage in securities lending. Securities lending involves the risk that the Fund or the Underlying Funds may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund or the Underlying Funds 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 or an Underlying Fund. Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders. Structural Risk. The countries in which the Fund or an Underlying Fund invests may be subject to considerable degrees of economic, political and social instability. Tax Risk. Because the Fund is expected to invest in the Underlying Funds, the Fund’s realized losses on sales of shares of an Underlying Fund may be indefinitely or permanently deferred as “wash sales.” Distributions of short-term capital gains by an Underlying Fund will be recognized as ordinary income by the Fund and would not be offset by the Fund’s capital loss carryforwards, if any. Capital loss carryforwards of an Underlying Fund, if any, would not offset net capital gains of the Fund. Tracking Error Risk. The Fund may be subject to tracking error, which is the divergence of a fund’s performance from that of the 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 Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of dividends or interest, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the 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 Underlying Index does not. The Underlying Funds are also subject to tracking error risk in seeking to track their own performance of the applicable underlying indexes. Valuation Risk. The price the Fund or an Underlying Fund could receive upon the sale of a security or other asset may differ from the Fund's or the Underlying Fund's valuation of the security or other asset and from the value used by the Underlying Index, particularly for securities or other assets that trade in low volume or volatile markets or that are valued using a fair value methodology as a result of trade suspensions or for other reasons. In addition, the value of the securities or other assets in the Fund's or an Underlying Fund's portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund's or an Underlying Fund's shares. Authorized Participants who purchase or redeem shares of the Fund or an Underlying Fund on days when the Fund or an Underlying Fund is holding fair-valued securities may receive fewer or more shares, or lower or higher redemption proceeds, than they would have received had the Fund or an Underlying Fund not fair-valued securities or used a different valuation methodology. The Fund’s or an Underlying Fund's ability to value investments may be impacted by technological issues or errors by pricing services or other third-party service providers.
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	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
iShares ESG Aware Aggressive Allocation ETF \| iShares ESG Aware Aggressive Allocation ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.18%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.16%
Total Annual FundOperatingExpenses	rr_ExpensesOverAssets	0.34%
Fee Waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.16%)
Total Annual Fund Operating Expenses after Fee Waiver	rr_NetExpensesOverAssets	0.18%
1 Year	rr_ExpenseExampleYear01	$ 18
3 Years	rr_ExpenseExampleYear03	$ 58

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

iSHARES TRUST

Prospectus Date

rr_ProspectusDate

Jun. 08, 2020

iShares ESG Aware Aggressive Allocation ETF

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

iShares ESG Aware Aggressive Allocation ETF Ticker: EAOA Stock Exchange: Cboe BZX

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The iShares ESG Aware Aggressive Allocation ETF (the “Fund”) seeks to track the investment results of an index composed of a portfolio of underlying equity and fixed income funds with positive environmental, social, and governance characteristics intended to represent an aggressive risk profile.

Expense [Heading]

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Fees and Expenses

Expense Narrative [Text Block]

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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. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”). BFA, the investment adviser to the Fund, has contractually agreed to waive a portion of its management fees in an amount equal to the Acquired Fund Fees and Expenses, if any, attributable to investments by the Fund in other series of the Trust and iShares, Inc. through November 30, 2025. The contractual waiver may be terminated prior to November 30, 2025 only upon written agreement of the Trust and BFA.

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]

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

Fee Waiver or Reimbursement over Assets, Date of Termination

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November 30, 2025

Portfolio Turnover [Heading]

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Portfolio Turnover.

Portfolio Turnover [Text Block]

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The Fund and the iShares funds in which the Fund invests (each, an “Underlying Fund” and collectively, the “Underlying Funds”), may pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolio). A higher portfolio turnover rate for the Fund or Underlying Funds may indicate higher transaction costs and may cause the Fund or Underlying Funds to incur increased expenses. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example (except costs to Underlying Funds included as part of Acquired Fund Fees and Expenses), affect the Fund’s performance. To the extent an Underlying Fund incurs costs from high portfolio turnover, such costs may have a negative effect on the performance of the Fund.

Expense Exchange Traded Fund Commissions [Text]

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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:

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

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Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).

Expense Example [Heading]

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Example.

Expense Example Narrative [Text Block]

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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]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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The Fund is a fund of funds and seeks to achieve its investment objective by investing primarily in Underlying Funds that themselves seek investment results corresponding to their own respective underlying indexes each of which takes into account ESG characteristics. The Underlying Funds invest primarily in companies or issuers that exhibit positive ESG characteristics, as identified by the index provider of each Underlying Fund in distinct asset classes, such as large-, mid- or small-capitalization U.S. or non-U.S. equity, and the broad U.S. dollar-denominated investment-grade bond market; each such asset class has its own risk profile.

The BlackRock ESG Aware Aggressive Allocation Index (the “Underlying Index”) is composed of a portfolio of ESG-oriented equity and fixed income Underlying Funds and measures the performance of BIS’s fixed allocation strategy that is intended to represent an “aggressive” risk profile with an 80% allocation to equities and 20% allocation to fixed income, as defined by BIS. BIS’s estimation of an aggressive risk profile may differ from your own. The Underlying Index is rebalanced semi-annually after the market close on the last business day of April and October.

At each rebalancing, the Fund will adjust its portfolio to align with the 20% allocation to fixed income and 80% allocation to equity prescribed by the Index Provider. The Fund's allocation to fixed income and equity may fluctuate due to appreciation or depreciation in the market value of the Fund's assets. At each rebalance, the Underlying Index will include a fixed allocation of 80% of its assets in Underlying Funds that invest primarily in equity securities and 20% of its assets in Underlying Funds that invest primarily in U.S. dollar-denominated investment-grade bonds. As of May 11, 2020, the Underlying Index was comprised of approximately 80.94% of its assets in Underlying Funds that invest primarily in equity securities and 19.06% of its assets in Underlying Funds that invest primarily in U.S. dollar-denominated investment-grade bonds.

As of May 11, 2020, the Underlying Index was comprised of the iShares ESG MSCI USA ETF, iShares ESG MSCI USA Small-Cap ETF, iShares ESG MSCI EAFE ETF, iShares ESG MSCI EM ETF, and iShares ESG U.S. Aggregate Bond ETF. As of May 11, 2020, a significant portion of the Underlying Index is represented by securities of companies in the information technology industry or sector. The components of the Underlying Index are unlikely 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 aiming to keep 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 an applicable 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 an applicable underlying index. The Fund and an Underlying Fund may or may not hold all of the securities in the applicable Underlying Index.

The Fund will invest at least 80% of its assets, exclusive of collateral held from securities lending, in the component securities of the Underlying Index and may invest up to 20% of its assets in certain index futures, options, options on index futures, swap contracts or other derivatives, as related to its Underlying Index and its component securities, cash and cash equivalents, other investment companies, as well as in securities and other instruments 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 the Index Provider, an affiliated person of the Fund and of BFA, the Fund's investment adviser. 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]

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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]

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Summary of Principal Risks

Risk Narrative [Text Block]

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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 (either directly or through its investments in the Underlying Funds), 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. The order of the below risk factors does not indicate the significance of any particular risk factor.

Affiliated Fund Risk. In managing the Fund, BFA will have the ability to select Underlying Funds and substitute Underlying Funds with other exchange-traded funds (“ETFs”) that it believes will achieve the Fund’s objective. BFA may be subject to potential conflicts of interest in selecting Underlying Funds and substituting Underlying Funds with other ETFs because the fees paid to BFA by some Underlying Funds and other ETFs managed by BFA may be higher than the fees paid by other Underlying Funds. If an Underlying Fund or other ETF holds interests in an affiliated fund in excess of a certain amount, the Fund may be prohibited from purchasing shares of that Underlying Fund or other ETF.

Allocation Risk. The Fund’s ability to achieve its investment objective depends upon the Index Provider's ability to develop a model that accurately assesses the Fund’s asset class allocation and selects the best mix of Underlying Funds and other ETFs. There is a risk that the Index Provider's evaluations and assumptions regarding asset classes or Underlying Funds, which are utilized as inputs in the model, may be incorrect in view of actual market conditions.

Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's or an Underlying 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), 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 to allow 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 (as defined in the Creations and Redemptions section of this prospectus (the “Prospectus”)) may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. 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 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 or delisting. Authorized Participant concentration risk may be heightened for ETFs, such as the Fund, that invest in securities issued by non-U.S. issuers or other securities or instruments that have lower trading volumes.

Calculation Methodology Risk. The Underlying Index relies on various sources of information to assess the criteria of issuers included in the Underlying Index, including information that may be based on assumptions and estimates. Neither the Fund nor BFA can offer assurances that the Underlying Index’s calculation methodology or sources of information will provide an accurate assessment of included issuers.

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 or an Underlying Fund's investments are concentrated in the securities and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Credit Risk. Debt issuers and other counterparties may be unable or unwilling to make timely interest and/or principal payments when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s or an Underlying Fund's investment in that issuer. The degree of credit risk depends on an issuer's or counterparty's financial condition and on the terms of an obligation.

Currency Risk. Because the Fund's and the Underlying Funds' NAVs are determined in U.S. dollars, the Fund's NAV could decline if a currency of a non-U.S. market in which a Fund or an Underlying Fund invests depreciates against the U.S. dollar or if there are delays or limits on repatriation of such currency. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the Fund's NAV may change quickly and without warning.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund or the Underlying Funds, the Funds' or the Underlying Funds' adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result 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 cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Derivatives Risk. The Fund or an Underlying Fund may invest in certain types of derivatives contracts, including futures, options and swaps, which can be more sensitive to changes in interest rates or to sudden fluctuations in market prices than conventional securities, which can result in greater losses to the Fund.

Equity Securities Risk. Equity securities are subject to changes in value, and their values may be more volatile than those of other asset classes. Certain Underlying Funds invest in common stocks, which generally subject their holders to more risks than preferred stocks and debt securities because common stockholders’ claims are subordinated to those of holders of preferred stocks and debt securities upon the bankruptcy of the issuer.

ESG Investment Strategy Risk. The Fund’s ESG investment strategy limits the types and number of investment opportunities available to the Fund and, as a result, the Fund may underperform other funds that do not have an ESG focus. The Fund’s ESG investment strategy may result in the Fund investing in securities or industry sectors that underperform the market as a whole or underperform other funds screened for ESG standards. In addition, companies selected by the Index Provider may not exhibit positive or favorable ESG characteristics.

Geographic Risk. A natural disaster could occur in a geographic region in which the Fund or an Underlying Fund invests, which could adversely affect the economy or the business operations of companies in the specific geographic region, causing an adverse impact on the Fund's or an Underlying Fund's investments in, or which are exposed to, the affected region.

High Portfolio Turnover Risk. High portfolio turnover (considered by the Fund and the Underlying Funds to mean higher than 100% annually) may result in increased transaction costs to the Fund or an Underlying Fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities.

Income Risk. The Fund's income may decline if interest rates fall. This decline in income can occur because the Fund or an Underlying Fund may subsequently invest in lower-yielding bonds when bonds in its portfolio mature, are near maturity or are called, bonds in the Underlying Index are substituted, or the Fund or an Underlying Fund otherwise needs to purchase additional bonds.

Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will 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 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. Because the Underlying Index is a new index and the Index Provider is also new to creation of securities indexes, there may be a greater risk that index errors will not be detected as quickly as they might be in the case of an index that has been maintained over time by a long-standing index provider. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition.

Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts.

Information Technology Sector Risk. Information technology companies face intense competition and potentially rapid product obsolescence. They are also heavily dependent on intellectual property rights and may be adversely affected by the loss or impairment of those rights. Companies in the information technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action. Companies in the software industry may be adversely affected by, among other things, the decline or fluctuation of subscription renewal rates for their products and services and actual or perceived vulnerabilities in their products or services.

Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates.

Investment in Underlying Funds Risk. The Fund invests substantially all of its assets in the Underlying Funds, so the Fund’s investment performance is directly related to the performance of the Underlying Funds. The Fund’s NAV will change with changes in the value of the Underlying Funds and other securities in which the Fund invests based on their market valuations. An investment in the Fund will entail more costs and expenses than a direct investment in the Underlying Funds.

As the Underlying Funds, or the Fund’s allocations among the Underlying Funds, change from time to time, or to the extent that the total annual fund operating expenses of any Underlying Fund changes, the weighted average operating expenses borne by the Fund may increase or decrease.

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund or an Underlying 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 or the Underlying Funds will not fully replicate their respective indexes, they are subject to the risk that BFA's investment strategy may not produce the intended results.

Market Risk. The Fund and the Underlying Funds could lose money over short periods due to short-term market movements and over longer periods during more prolonged market downturns. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund and the Underlying Funds face numerous market trading risks, including the potential lack of an active market for their 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.

Model Risk. Neither the Fund nor BFA can offer assurances that the Underlying Index's allocation model will achieve its intended results or maximize returns or minimize risk, or be appropriate for every investor seeking a particular risk profile.

National Closed Market Trading Risk. To the extent that the underlying securities and/or other assets held by the Fund or the Underlying Funds trade on foreign exchanges or in foreign markets that may be closed when the securities exchange on which the Fund’s or an Underlying Fund's shares trade is open, there are likely to be deviations between the current price of such an underlying security and the last quoted price for the underlying security (i.e., the Fund’s or an Underlying Fund's quote from the closed foreign market). These deviations could result in premiums or discounts to the Fund’s or an Underlying Fund's NAV that may be greater than those experienced by other ETFs.

Non-U.S. Issuers Risk. Securities issued by non-U.S. issuers carry different risks from securities issued by U.S. issuers. These risks 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.

Non-U.S. Securities Risk. Investments in the securities of non-U.S. issuers are subject to the risks associated with investing in those non-U.S. markets, such as heightened risks of inflation or nationalization. The Fund or an Underlying Fund may lose money due to political, economic and geographic events affecting issuers of non-U.S. securities or non-U.S. markets. In addition, non-U.S. securities markets may trade a small number of securities and may be unable to respond effectively to changes in trading volume, potentially making prompt liquidation of holdings difficult or impossible at times. The Fund is specifically exposed to European Economic Risk.

Operational Risk. The Fund and the Underlying Funds are 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, the Underlying Funds 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 significant operational risks.

Passive Investment Risk. The Fund and the Underlying Funds are not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets.

Prepayment Risk. During periods of falling interest rates, issuers of certain debt obligations may repay principal prior to the security’s maturity, which may cause the Fund and the Underlying Funds to have to reinvest in securities with lower yields or higher risk of default, resulting in a decline in the Fund’s income or return potential.

Privately Issued Securities Risk. The Fund or the Underlying Funds 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 may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund.

Reinvestment Risk. The Fund or an Underlying Fund may invest a portion of its assets in short-term fixed-income instruments and, as a result, may be adversely affected if interest rates fall because they may have to invest in lower-yielding bonds as bonds mature.

Reliance on Trading Partners Risk. The Fund and certain Underlying Funds invest in countries or regions whose economies are heavily dependent upon trading with key partners. Any reduction in this trading may have an adverse impact on the Fund's investments. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk, European Economic Risk and U.S. Economic Risk.

Risk of Investing in Developed Countries. The Fund’s or an Underlying Fund's investment in developed country issuers may subject the Fund to regulatory, political, currency, security, economic and other risks associated with developed countries. Developed countries tend to represent a significant portion of the global economy and have generally experienced slower economic growth than some less developed countries. Certain developed countries have experienced security concerns, such as terrorism and strained international relations. Incidents involving a country’s or region’s security may cause uncertainty in its markets and may adversely affect its economy and the Fund’s or an Underlying Fund's investments. In addition, developed countries may be adversely impacted by changes to the economic conditions of certain key trading partners, regulatory burdens, debt burdens and the price or availability of certain commodities.

Risk of Investing in the U.S. 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 or the Underlying Funds has exposure.

Securities Lending Risk. The Fund or an Underlying Fund may engage in securities lending. Securities lending involves the risk that the Fund or the Underlying Funds may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund or the Underlying Funds 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 or an Underlying Fund.

Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders.

Structural Risk. The countries in which the Fund or an Underlying Fund invests may be subject to considerable degrees of economic, political and social instability.

Tax Risk. Because the Fund is expected to invest in the Underlying Funds, the Fund’s realized losses on sales of shares of an Underlying Fund may be indefinitely or permanently deferred as “wash sales.” Distributions of short-term capital gains by an Underlying Fund will be recognized as ordinary income by the Fund and would not be offset by the Fund’s capital loss carryforwards, if any. Capital loss carryforwards of an Underlying Fund, if any, would not offset net capital gains of the Fund.

Tracking Error Risk. The Fund may be subject to tracking error, which is the divergence of a fund’s performance from that of the 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 Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of dividends or interest, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the 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 Underlying Index does not. The Underlying Funds are also subject to tracking error risk in seeking to track their own performance of the applicable underlying indexes.

Valuation Risk. The price the Fund or an Underlying Fund could receive upon the sale of a security or other asset may differ from the Fund's or the Underlying Fund's valuation of the security or other asset and from the value used by the Underlying Index, particularly for securities or other assets that trade in low volume or volatile markets or that are valued using a fair value methodology as a result of trade suspensions or for other reasons. In addition, the value of the securities or other assets in the Fund's or an Underlying Fund's portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund's or an Underlying Fund's shares. Authorized Participants who purchase or redeem shares of the Fund or an Underlying Fund on days when the Fund or an Underlying Fund is holding fair-valued securities may receive fewer or more shares, or lower or higher redemption proceeds, than they would have received had the Fund or an Underlying Fund not fair-valued securities or used a different valuation methodology. The Fund’s or an Underlying Fund's ability to value investments may be impacted by technological issues or errors by pricing services or other third-party service providers.

Risk Lose Money [Text]

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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]

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Performance Information

Performance Narrative [Text Block]

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As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.

Performance One Year or Less [Text]

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As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.

iShares ESG Aware Aggressive Allocation ETF | iShares ESG Aware Aggressive Allocation ETF

Risk/Return:

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Management Fees

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0.18%

Distribution and Service (12b-1) Fees

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none

Other Expenses

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none