| Label | Element | Value | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| iShares iBonds Dec 2027 Term Muni Bond ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk/Return [Heading] | rr_RiskReturnHeading | iSHARES® iBONDS® DEC 2027 TERM MUNI BOND ETF Ticker: IBMPStock Exchange: Cboe BZX | |||||||||||||
| Objective [Heading] | rr_ObjectiveHeading | Investment Objective | |||||||||||||
| Objective, Primary [Text Block] | rr_ObjectivePrimaryTextBlock | The iShares iBonds Dec 2027 Term Muni Bond ETF (the “Fund”) seeks to track the investment results of an index composed of investment-grade U.S. municipal bonds expected to mature or be redeemed before December 2, 2027.
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| 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 buy, hold and sell 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: (i) the management fees, (ii) interest expenses, (iii) taxes, (iv) expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, (v) distribution fees or expenses, and (vi) litigation expenses and any extraordinary expenses. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
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| 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)1 | |||||||||||||
| 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 the 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 3% of the average value of its portfolio. | |||||||||||||
| Portfolio Turnover, Rate | rr_PortfolioTurnoverRate | 3.00% | |||||||||||||
| Expense Example [Heading] | rr_ExpenseExampleHeading | Example. | |||||||||||||
| Expense Example Narrative [Text Block] | rr_ExpenseExampleNarrativeTextBlock | This Example is intended to help you compare the cost of 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.Fund expenses (and any applicable waivers) are calculated only through December 15, 2027 because the Fund is scheduled to cease operations and liquidate by that date. 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 S&P AMT-Free Municipal Series Callable-Adjusted Dec 2027 IndexTM (the “Underlying Index”), which measures the performance of investment-grade (as determined by S&P Dow Jones Indices LLC (the “Index Provider” or “SPDJI”)), tax-exempt, U.S. municipal bonds, reducing callable bonds before 2027, and only including non-callable bonds maturing in 2027. As of October 31, 2024, there were 13,184 issues in the Underlying Index. The Underlying Index includes municipal bonds primarily from issuers that are U.S. state, federal district (the District of Columbia), or local government or agency such that the interest on the bonds is exempt from U.S. federal income taxes and the federal alternative minimum tax (“AMT”). Bonds issued by U.S. territories and the Commonwealth of Puerto Rico are excluded from the Underlying Index. Each bond must have a rating of at least BBB- by S&P Global Ratings, Baa3 by Moody’s Investors Service, Inc., or BBB- by Fitch Ratings, Inc. and must have a minimum maturity par amount of $2 million to be eligible for inclusion in the Underlying Index. To remain in the Underlying Index, bonds must maintain a minimum par amount greater than or equal to $2 million as of each rebalancing reference date. All non-callable bonds in the Underlying Index will mature or be redeemed after December 31, 2026 and before December 2, 2027. Callable bonds are eligible subject to the following: (i) a final maturity date after December 31, 2026 and before December 2, 2027, and a next call date no sooner than two years prior to index maturity year; or (ii) a final maturity up to four years after the index maturity year, if the next call date is within the index maturity range. In the Underlying Index year of maturity, bonds that mature or are pre-refunded in their respective year of maturity do not accrue interest past the maturity or pre-refund date. A bond is “pre-refunded” when the bond has been refunded to a call date prior to maturity. In other words, a holder of a “pre-refunded” bond receives all payments of interest and principal back on an earlier date then the stated maturity date of the bond. All payments related to the maturity or pre-refunding of a bond are reinvested in tax-exempt cash or cash equivalents for the duration of each month. Outside of five years prior to the term of the Fund, the Underlying Index will be market value weighted. Five years prior to the term of the Fund, monthly rebalances occurring in rolling two year periods will remove bonds with a maturity year outside the term of the Fund from the Underlying Index. Such rebalancing will begin with those bonds whose effective maturity date is furthest from that of the Underlying Index. Each two year period will remove bonds scheduled to mature in a specific year outside the term of the Fund. For example, bonds scheduled to mature in 2031 will be removed from the Underlying Index over the course of a two year period beginning in January 2022. As a result, as of January 1, 2027, the Underlying Index will not contain bonds with an effective maturity date later than December 2, 2027. The Fund is a series of the iShares iBonds® fixed maturity series of bond exchange-traded funds (“ETFs”) sponsored by BlackRock, Inc. (“BlackRock”). The iBonds® fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation. The Fund does not invest in U.S. federal government agency bonds. BFA uses an indexing approach to try to achieve the Fund’s investment objective. 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 value and industry weightings), fundamental characteristics (such as return variability, duration (i.e., a security's price sensitivity to a change in interest rates), maturity or credit ratings and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the securities in the Underlying Index. The Fund will invest at least 80% of its assets in the component securities of the Underlying Index, and the Fund will invest at least 90% of its assets in fixed income securities of the types included in the Underlying Index that BFA believes will help the Fund track the Underlying Index, in each case except during the last months of the Fund's operations, as described below. The Fund will invest no more than 10% of its assets in futures, options and swaps contracts that BFA believes will help the Fund track the Underlying Index as well as in fixed income securities other than the types included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. Cash and cash equivalent investments associated with a derivative position will be treated as part of that position for the purposes of calculating the percentage of investments included in the Underlying Index. The Fund will generally hold municipal bond securities issued by state and local municipalities whose interest payments are exempt from U.S. federal income tax, the federal AMT and the federal Medicare contribution tax of 3.8% on “net investment income,” including dividends, interest and capital gains. In the last months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested in bonds but instead will be held in cash and cash equivalents, including, without limitation, shares of money market funds advised by BFA or its affiliates, AMT-free tax-exempt municipal notes, variable rate demand notes and obligations, tender option bonds and municipal commercial paper. These cash equivalents may not be included in the Underlying Index. By December 2, 2027, the Underlying Index is expected to consist entirely of cash earned in this manner. Around the same time, the Fund will wind up and terminate. After appropriate provision is made for any Fund liabilities, its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund's termination was approved by a majority of the Trust's Board of Trustees (the “Board”) and does not require additional approval by Fund shareholders. The Board may extend the termination date if a majority of the Board determines the extension to be in the best interest of the Fund. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that converts fund assets to conservative investments over time. 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), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry.
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| 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), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry. | |||||||||||||
| Risk [Heading] | rr_RiskHeading | Summary of Principal Risks | |||||||||||||
| Bar Chart and Performance Table [Heading] | rr_BarChartAndPerformanceTableHeading | Performance Information | |||||||||||||
| Performance Narrative [Text Block] | rr_PerformanceNarrativeTextBlock | The performance information below illustrates how the Fund’s performance has varied over different periods and provides some indication of the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table compares the Fund’s performance to that of an appropriate broad-based securities market index and the Underlying Index. Fund returns assume the reinvestment of any dividends and distributions. The Fund’s returns reflect the impact of any agreements to waive or reimburse expenses, which would reduce performance if not in effect. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information, including the Fund’s current NAV, may be obtained by visiting www.iShares.com or by calling 1-800-iShares (1-800-474-2737) (toll free).
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| Performance Information Illustrates Variability of Returns [Text] | rr_PerformanceInformationIllustratesVariabilityOfReturns | The performance information below illustrates how the Fund’s performance has varied over different periods and provides some indication of the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table compares the Fund’s performance to that of an appropriate broad-based securities market indexand the Underlying Index. | |||||||||||||
| 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 | Calendar Year-by-Year Returns | |||||||||||||
| Bar Chart Closing [Text Block] | rr_BarChartClosingTextBlock |
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| Performance Table Heading | rr_PerformanceTableHeading | Average Annual Total Returns (for the periods ended December 31, 2024) | |||||||||||||
| 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 sales 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. | |||||||||||||
| Performance Table Narrative | rr_PerformanceTableNarrativeTextBlock | 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 sales 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.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Risk Lose Money [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | 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. | |||||||||||||
| iShares iBonds Dec 2027 Term Muni Bond ETF | Municipal Securities Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Municipal Securities Risk. Municipal securities can be significantly affected by political or economic changes, including changes made in the law after issuance of the securities, as well as uncertainties in the municipal market related to taxation, legislative changes or the rights of municipal security holders, including in connection with an issuer insolvency. Municipal securities backed by current or anticipated revenues from a specific project or specific assets can be negatively affected by the inability to collect revenues from such projects or assets. Certain municipal securities are issued by entities with limited taxing authority such as school districts, or are dependent on revenue from a particular sector or industry, such as the utilities sector, infrastructure sector, or transportation industry. In the event of a default or insolvency, certain issuers of municipal bonds may be subject to proceedings other than those specified by U.S. bankruptcy laws, which may impact the Fund’s ability to ultimately recover assets.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Risk of Investing in the U S [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Risk of Investing in the U.S. Investing in U.S. issuers subjects the Fund to legal, regulatory, political, currency, security, and economic risks that are specific to the U.S. Certain changes in the U.S., such as a weakening of the U.S. economy or a decline in its financial markets, may have an adverse effect on U.S. issuers.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Interest Rate Risks [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Interest Rate Risk. Interest rate risk refers to the risk of fluctuations in the value of a fixed-income security due to changes in the general level of interest rates. Interest rate changes can be sudden and unpredictable and are influenced by a number of factors, including government policy, monetary policy, inflation expectations, perceptions of risk, and supply and demand for fixed-income securities. An increase in interest rates generally will cause the value of fixed-income securities to decline. Securities with longer maturities generally are more sensitive to interest rate changes and subject to greater fluctuations in value. Changes in interest rates may have unpredictable effects on fixed-income markets and result in heightened volatility and lower liquidity for certain instruments, which may adversely affect a Fund’s performance. During periods of very low or negative interest rates, a Fund may be unable to maintain positive returns or pay dividends to shareholders.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Market Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | 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. Local, regional or global events such as war, acts of terrorism, pandemics or other public health issues, recessions, the prospect or occurrence of a sovereign default or other financial crisis, 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.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Index Related Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Index-Related Risk. The Index Provider may rely on various sources of information to assess the criteria of components of the Underlying Index, including information that may be based on assumptions and estimates. Neither the Fund nor BFA can offer assurances that the Index Provider’s methodology or sources of information will provide an accurate assessment of included components or will result in the Fund meeting its investment objective. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur, and the Index Provider may not identify or correct them promptly or at all, which may have an adverse impact on the Fund and its shareholders. Unusual market conditions or other unforeseen circumstances (such as natural disasters, political unrest or war) may impact the Index Provider or a third-party data provider and could cause the Index Provider to postpone a scheduled rebalance. This could cause the Underlying Index to vary from its normal or expected composition.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Asset Class Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Asset Class Risk. The securities and other assets in the Underlying Index or in the Fund’s portfolio may underperform in comparison to financial markets generally, a particular financial market, another index, or other asset classes.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Authorized Participant Concentration Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Authorized Participant Concentration Risk. An “Authorized Participant” is a member or participant of a clearing agency registered with the SEC, which has a written agreement with the Fund or one of its service providers that allows the Authorized Participant to place orders for the purchase and redemption of creation units (“Creation Units”). Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund. There are a limited number of institutions that may act as Authorized Participants for the Fund, including on an agency basis on behalf of other market participants. No Authorized Participant is obligated to engage in creation or redemption transactions. To the extent that Authorized Participants exit the business or do not place creation or redemption orders for the Fund and no other Authorized Participant places orders, Fund shares are more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Call Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Call Risk. During periods of falling interest rates, an issuer of a callable bond held by the Fund may “call” or repay the security before its stated maturity, and the Fund may have to reinvest the proceeds in securities with lower yields, which would result in a decline in the Fund's income, or in securities with greater risks or with other less favorable features. Issuers of longer maturity securities may be more likely to call such securities as interest rates fall. As a result, the Fund's investment in certain callable securities maturing outside the term of the Fund may increase the likelihood that securities held by the Fund are called prior to December 2, 2027.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Concentration Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | 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 or other assets of one or more issuers, countries or other geographic units, markets, industries, project types, or asset classes.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Credit Risks [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | 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 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.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Cybersecurity Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, its adviser, distributor, Index Provider, other service providers, counterparties, or issuers of assets in which the Fund invests may cause disruptions that negatively impact 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. The Fund cannot control the cybersecurity plans and systems of its service providers, counterparties, and other third parties whose activities affect the Fund. In addition, cyber incidents may adversely impact the issuers of securities in which the Fund invests, which may cause such investments to lose value.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Declining Yield Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Declining Yield Risk. During the final eleven months prior to the Fund's planned termination date, its yield will generally tend to move toward prevailing money market rates and may be lower than the yields of the bonds previously held by the Fund and lower than prevailing yields for bonds in the market.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Fluctuation of Yield and Liquidation Amount Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Fluctuation of Yield and Liquidation Amount Risk. The Fund, unlike a direct investment in a municipal bond that has a level coupon payment and a fixed payment at maturity, will make distributions of income that vary over time. It is expected that an investment in the Fund, if held through maturity, will produce aggregate returns comparable to a direct investment in a group of municipal bonds of similar credit quality and maturity. Unlike a direct investment in municipal bonds, the breakdown of returns between Fund distributions and liquidation proceeds are not predictable at the time of your investment. For example, at times during the Fund's existence it may make distributions at a greater (or lesser) rate than the coupon payments received on the Fund's portfolio, which would result in the Fund returning a lesser (or greater) amount on liquidation than would otherwise be the case. The rate of Fund distribution payments may adversely affect the tax characterization of your returns from an investment in the Fund relative to a direct investment in municipal bonds. If the amount you receive as liquidation proceeds upon the Fund's termination is higher or lower than your cost basis, you may experience a gain or loss for tax purposes.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Illiquid Investments Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Illiquid Investments Risk. An illiquid investment is any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without significantly changing the market value of the investment. To the extent the Fund holds illiquid investments, the illiquid investments may reduce its returns because the Fund may be unable to transact at advantageous times or prices. In addition, if the Fund is limited in its ability to sell illiquid investments during periods when shareholders are redeeming their shares, it will need to sell liquid securities to meet redemption requests and illiquid securities will become a larger portion of the Fund’s holdings. During periods of market volatility, liquidity in the market for Fund shares may be impacted by the liquidity in the market for the underlying securities or other assets held by the Fund, which could lead to Fund shares trading at a premium or discount to the Fund’s NAV.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Income Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Income Risk. The Fund's income may decline if interest rates fall. This decline in income can occur because the Fund may subsequently invest in lower-yielding bonds as bonds in its portfolio mature, are near maturity or are called, bonds in the Underlying Index are substituted, or the Fund otherwise needs to purchase additional bonds.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Issuer Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Issuer Risk. The performance of the Fund depends on the performance of individual securities or other assets to which the Fund has exposure. The value of securities or other assets may decline, or perform differently from the market as a whole, due to changes in the financial condition or credit rating of the issuer or counterparty.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Large Shareholder and Large Scale Redemption Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Large Shareholder and Large-Scale Redemption Risk. Certain shareholders of the Fund, including an Authorized Participant, a third-party investor, the Fund’s adviser, an affiliate of the Fund’s adviser, a market maker, or another entity, may from time to time own or manage a substantial amount of Fund shares, or may hold their investment in the Fund for a limited period of time. There can be no assurance that any large shareholder or large group of shareholders would not redeem their investment. Redemptions of a large number of Fund shares could require the Fund to dispose of assets to meet the redemption requests, which can accelerate the realization of taxable income and/or capital gains and cause the Fund to make taxable distributions to its shareholders earlier than the Fund otherwise would have. In addition, under certain circumstances, non-redeeming shareholders may be treated as receiving a disproportionately large taxable distribution during or with respect to such year. In some circumstances, the Fund may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns. These large redemptions may also force the Fund to sell portfolio securities or other assets when it might not otherwise do so, which may negatively impact the Fund’s NAV, increase the Fund’s brokerage costs and/or have a material effect on the market price of Fund shares.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Management Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Management Risk. The Fund generally does not attempt to take defensive positions under any market conditions, including declining markets. As the Fund will not fully replicate the Underlying Index and may hold securities or other assets not included in the Underlying Index, it is subject to the risk that the investment strategy of BFA may not produce the intended results. 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.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Market Trading Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares (including through a trading halt), losses from trading in secondary markets, periods of high volatility, and disruptions in the process of creating and redeeming Fund shares. Any of these factors, among others, may lead to the Fund’s shares trading in the secondary market at a premium or discount to NAV or to the intraday value of the Fund’s portfolio holdings. If you buy Fund shares at a time when the market price is at a premium to NAV or sell Fund shares at a time when the market price is at a discount to NAV, you may pay significantly more or receive significantly less than the underlying value of the Fund shares.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Operational Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | 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 significant operational risks.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Tax Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Tax Risk. There is no guarantee that the Fund's income will be exempt from U.S. federal income taxes, the federal AMT or the federal Medicare contribution tax of 3.8% on “net investment income.”
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Tracking Error Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Tracking Error Risk. The Fund may be subject to “tracking error,” which is the divergence of the Fund’s performance from that of the Underlying Index. Tracking error may occur due to a number of factors, including differences between the securities and other assets held in the Fund’s portfolio and those included in the Underlying Index; differences in the timing and methodologies used to value securities and other assets; transaction costs and other expenses incurred by the Fund that the Underlying Index does not incur; the Fund’s holding of uninvested cash; differences in the timing of the accrual or the valuation of dividends or interest received by the Fund or distributions paid to Fund shareholders; tax gains or losses; the requirements for the Fund to maintain pass-through tax treatment; portfolio transactions carried out to minimize the distribution of capital gains to shareholders; the acceptance of custom baskets; changes to the Underlying Index; and impacts to the Fund of complying with certain regulatory requirements or limits. Tracking error risk may be heightened during times of increased market volatility or other unusual market conditions. A Fund that tracks an index where municipal bonds are an investment focus may experience higher tracking error than ETFs that do not track such indexes.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | Valuation Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Valuation Risk. The price that the Fund could receive upon the sale (or other disposition) of a security or other asset may differ from the Fund’s valuation of the security or other asset, particularly for securities or other assets that trade in low volume or volatile markets or that are valued using a fair value methodology. The price received by the Fund also may differ from the value used by the Underlying Index. In addition, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when investors are not able to purchase or sell Fund shares. Authorized Participants that create or redeem Fund shares on days when the Fund is holding fair-valued securities or other assets may receive fewer or more shares, or lower or higher redemption proceeds, than they would have received had the securities or other assets not been fair valued or been valued using a different methodology. The ability to value investments may be impacted by technological issues or errors by pricing services or other third-party service providers.
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| iShares iBonds Dec 2027 Term Muni Bond ETF | iShares iBonds Dec 2027 Term Muni Bond ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Management Fees | rr_ManagementFeesOverAssets | 0.18% | [1] | ||||||||||||
| Distribution and Service (12b-1) Fees | rr_DistributionAndService12b1FeesOverAssets | none | [1] | ||||||||||||
| Other Expenses | rr_OtherExpensesOverAssets | none | [1],[2] | ||||||||||||
| Total Annual Fund Operating Expenses | rr_ExpensesOverAssets | 0.18% | [1] | ||||||||||||
| 1 Year | rr_ExpenseExampleYear01 | $ 18 | |||||||||||||
| Maturity | ist_ExpenseExampleMaturity | $ 54 | |||||||||||||
| 2020 | rr_AnnualReturn2020 | 6.09% | |||||||||||||
| 2021 | rr_AnnualReturn2021 | (0.21%) | |||||||||||||
| 2022 | rr_AnnualReturn2022 | (6.00%) | |||||||||||||
| 2023 | rr_AnnualReturn2023 | 3.42% | |||||||||||||
| 2024 | rr_AnnualReturn2024 | 1.41% | |||||||||||||
| Highest Quarterly Return, Label | rr_HighestQuarterlyReturnLabel | Best Quarter | |||||||||||||
| Highest Quarterly Return, Date | rr_BarChartHighestQuarterlyReturnDate | Dec. 31, 2023 | |||||||||||||
| Highest Quarterly Return | rr_BarChartHighestQuarterlyReturn | 4.46% | |||||||||||||
| Lowest Quarterly Return, Label | rr_LowestQuarterlyReturnLabel | Worst Quarter | |||||||||||||
| Lowest Quarterly Return, Date | rr_BarChartLowestQuarterlyReturnDate | Mar. 31, 2022 | |||||||||||||
| Lowest Quarterly Return | rr_BarChartLowestQuarterlyReturn | (5.76%) | |||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 1.41% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 0.86% | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | 1.64% | |||||||||||||
| Inception Date | rr_AverageAnnualReturnInceptionDate | Apr. 09, 2019 | |||||||||||||
| iShares iBonds Dec 2027 Term Muni Bond ETF | Return After Taxes on Distributions | iShares iBonds Dec 2027 Term Muni Bond ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 1.41% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 0.86% | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | 1.64% | |||||||||||||
| iShares iBonds Dec 2027 Term Muni Bond ETF | Return After Taxes on Distributions and Sale of Fund Shares | iShares iBonds Dec 2027 Term Muni Bond ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 1.79% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 1.02% | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | 1.62% | |||||||||||||
| iShares iBonds Dec 2027 Term Muni Bond ETF | S&P Municipal Bond Index (Returns do not reflect deductions for fees, expenses or taxes) | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 1.53% | [3] | ||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 1.07% | [3] | ||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | 1.70% | [3] | ||||||||||||
| iShares iBonds Dec 2027 Term Muni Bond ETF | S&P AMT-Free Municipal Series Callable-Adjusted Dec 2027 Index (Returns do not reflect deductions for fees, expenses or taxes) | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 1.69% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 0.95% | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | 1.73% | |||||||||||||
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