| Label | Element | Value | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk/Return [Heading] | rr_RiskReturnHeading | iSHARES® 20+ YEAR TREASURY BOND BUYWRITE STRATEGY ETF Ticker: TLTWStock Exchange: Cboe BZX | |||||||||||||
| Objective [Heading] | rr_ObjectiveHeading | Investment Objective | |||||||||||||
| Objective, Primary [Text Block] | rr_ObjectivePrimaryTextBlock | The iShares 20+ Year Treasury Bond BuyWrite Strategy ETF (the “Fund”) seeks to track the investment results of an index that reflects a strategy of holding the iShares 20+ Year Treasury Bond ETF while writing (selling) one-month call options to generate income.
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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. 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 indirectly by the Fund as a result of investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the Fund's total return but is not included in the Fund's ratio of expenses to average net assets. Both figures are shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”). 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 apercentage of the value of your investments)1 | |||||||||||||
| Portfolio Turnover [Heading] | rr_PortfolioTurnoverHeading | Portfolio Turnover. | |||||||||||||
| Portfolio Turnover [Text Block] | rr_PortfolioTurnoverTextBlock | The Fund or the iShares 20+ Year Treasury Bond ETF (“TLT” or the “Underlying Fund”) may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate for the Fund or the Underlying Fund may indicate higher transaction costs and may cause the Fund or the Underlying Fund to incur increased expenses. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example(except costs to the Underlying Fund included as part of Acquired Fund Fees and Expenses), affect the Fund’s performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 0% of the average value of its portfolio. To the extent the Underlying Fund incurs costs from high portfolio turnover, such costs may have a negative effect on the performance of the Fund. | |||||||||||||
| Portfolio Turnover, Rate | rr_PortfolioTurnoverRate | none | |||||||||||||
| Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] | rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees | The impact of Acquired Fund Fees and Expenses is included in the Fund's total return but is not included in the Fund's ratio of expenses to average net assets. Both figures are 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 seeks to track the investment results of the Cboe TLT 2% OTM BuyWrite Index (the “Underlying Index”), which is provided by Cboe Global Indices, LLC (the “Index Provider” or “Cboe”) and is designed to measure the performance of a strategy of holding the Underlying Fund while writing (selling) one-month call options on the Underlying Fund to generate income. A strategy of holding a stock or basket of stocks and selling call options that reference the stock or basket of stocks is commonly known as a “covered call” or “buy-write” strategy. The Underlying Fund seeks to track the investment results of the ICE® U.S. Treasury 20+ Year Bond Index (the “Underlying Fund's underlying index”), which consists of publicly issued U.S. Treasury securities that have a remaining maturity of 20 or more years and have $300 million or more of outstanding face value, excluding amounts held by the Federal Reserve System. Index constituents also must be fixed-rate and denominated in U.S. dollars. Excluded from the Underlying Fund's underlying index are inflation-linked securities, Treasury bills, cash management bills, any government agency debt issued with or without a government guarantee and zero-coupon issues that have been stripped from coupon-paying bonds. The Underlying Fund's underlying index is market value weighted, and its constituents are updated on the last business day of each month. The Underlying Index utilizes “European-style” call options. Each call option in the Underlying Index has a strike price closest to 102% of the closing value of the Underlying Fund one day prior to the roll date. The roll date is the day that the Underlying Index closes out open call option positions by purchasing the offsetting call option positions and subsequently writes new call options that will expire the following month. The roll date is the business day preceding the expiration date of the options in the Underlying Index. The Fund will write options that trade on national securities exchanges. Although the Underlying Index will seek to select an option with a strike price closest to 102% of the closing value of the Underlying Fund one day prior to the roll date, if the premium that an option writer would hypothetically receive on the new 102% call option on the day prior to the roll date is below five basis points of the closing price of the Underlying Fund on the day prior to the roll date, the Underlying Index will instead select the call option with the strike price closest to 100% of the closing value of the Underlying Fund. The Underlying Index’s selection of an option with a strike price closest to 100% rather than 102% in these circumstances is designed to prevent the Underlying Index from “writing” an option that would cost an option writer more in potential trading costs than the option writer would receive in premium. Unlike American-style options, European-style options can only be exercised on the expiration date. The Fund will seek to write call options up to (but not exceeding) the full amount of shares of the Underlying Fund held in the Fund (i.e., the short position in the call option is offset, or “covered,” by the long position the Fund holds in shares of the Underlying Fund). In certain circumstances, the Fund may not write any options, primarily if the option is far “out of the money” (i.e., the strike price exceeds the price of the Underlying Fund) and would generate minimal premium income. By writing a call option, the Fund receives a premium and gives the purchaser of the option the right to purchase shares of the Underlying Fund at the strike price of the option at expiration. However, the Fund does not expect to physically settle outstanding option positions as it will generally purchase offsetting call options on the roll date as necessary to close out the open call position(s). By writing the call option(s), the Fund will not participate in market gains of the Underlying Fund above the strike price but will fully participate in any market losses if the Underlying Fund declines in value. The Fund may write options on different dates than the Underlying Index's roll date and may use strike prices, contract sizes, or maturity dates that are different than those for the options used in the Underlying Index. In addition, the Fund may write options that are not on the Underlying Fund but that have investment and fundamental characteristics, in the aggregate, similar to the options used in the Underlying Index. As of October 31, 2024, a significant portion of the Underlying Index is indirectly represented through its holdings in the Underlying Fund by publicly-issued U.S. Treasury securities. 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 and the Underlying 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 or other instruments 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 and the Underlying Fund may not hold all of the securities or other instruments in the applicable Underlying Index and may hold certain securities or other instruments that are not included in the applicable Underlying Index. The Underlying Index is sponsored by Cboe and is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.
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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) 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 | |||||||||||||
| 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy ETF | Covered Call Option Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Covered Call Option Risk. By writing covered call options in return for the receipt of premiums, the Fund will give up the opportunity to benefit from potential increases in the value of the Underlying Fund above the exercise prices of the written options, but will continue to bear the risk of declines in the value of the Underlying Fund. The premiums received from the options may not be sufficient to offset any losses sustained from the volatility of the Underlying Fund over time. In addition, the Fund’s ability to sell shares of the Underlying Fund will be limited while the option is in effect unless the Fund extinguishes the option position through the purchase of an offsetting identical option prior to the expiration of the written option. The covered call strategy may be subject to imperfect matching or price correlation between the written options and the Underlying Fund, which could reduce the Fund’s returns. Exchanges may suspend the trading of options (for example due to volatile markets or if trading in the Underlying Fund is halted). If trading is suspended, the Fund may be unable to write or purchase options at times that may be desirable or advantageous to the Fund to do so. If the Fund is unable to extinguish the option position before exercise, the Fund may be required to deliver the corresponding shares of the Underlying Fund, resulting in increased transaction costs, tracking error, underinvestment, and potentially the realization of capital gains. Further, this could lead to re-purchasing shares of the Underlying Fund or selling the corresponding options at a less favorable price than the fund might have received had the options been extinguished. The Fund uses options which are struck once per month, and the timing of changes in the price of the Underlying Fund may affect the Fund’s performance. For example, if the Underlying Fund experiences a drop in price followed by a quick rebound, the Fund may be unable to fully participate in the rebound if the rebound occurs immediately after the Fund’s roll date. In addition, if trading is suspended, the Fund may be unable to purchase an offsetting option for purposes of closing out an existing written option at the originally scheduled time and date. The Fund will be affected by movements in interest rates and bond yields and the resulting share price of the Underlying Fund. In a falling interest rate environment and other environments in which credit spreads narrow, the Underlying Fund is generally expected to appreciate in price, and the Fund may underperform the Underlying Fund as price appreciation for the Fund is limited to the exercise prices of the options written by the Fund.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | U S Treasury Obligations Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | U.S. Treasury Obligations Risk. U.S. Treasury obligations may differ from other securities in their interest rates, maturities, times of issuance and other characteristics and may provide relatively lower returns than those of other securities. Changes in the U.S. government’s financial condition or credit rating may cause the value of U.S. Treasury obligations to decline. Direct obligations of the U.S. Treasury have historically involved little risk of loss of principal if held to maturity, but the market value of such securities is not guaranteed and may fluctuate. Although U.S. Treasury obligations are backed by the full faith and credit of the United States, circumstances could arise that could prevent the timely payment of interest or principal.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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. Because the Index Provider is relatively new to the creation of indexes, these risks may be greater with respect to the Underlying Index than in the case of an index maintained by a long-standing index provider. 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy ETF | Derivatives Risks [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Derivatives Risk. The Fund’s use of derivatives (e.g., futures, forwards, swaps, options) may be riskier than other types of investments and may not have the intended effect on the Fund’s performance. Derivatives can be sensitive to changes in economic and market conditions, and they may increase the Fund’s volatility. The Fund also may experience reduced returns as a result of transaction costs and losses on derivatives positions. There is the risk of imperfect correlation between the value of a derivative and that of the asset underlying the derivative. Derivatives may create investment leverage, which could result in losses that significantly exceed the Fund’s original investment. Derivatives are subject to the risk of mispricing or improper valuation, particularly if there is not a liquid secondary market for the instrument. Certain derivatives are subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligations. The use of derivatives also exposes the Fund to additional operational and legal risks.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | Distribution Tax Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Distribution Tax Risk. The Fund currently expects to make distributions on a regular basis. While the Fund will normally pay its income as distributions, the Fund's distributions may exceed the Fund's income and gains for the Fund's taxable year. The Fund may be required to reduce its distributions if it has insufficient income. Distributions in excess of the Fund's current and accumulated earnings and profits will be treated as a return of capital. Distributions in excess of the Fund's minimum distribution requirements, but not in excess of the Fund's earnings and profits, will be taxable to Fund shareholders and will not constitute nontaxable returns of capital. A return of capital distribution generally will not be taxable but will reduce the shareholder's cost basis and will result in a higher capital gain or lower capital loss when those Fund shares on which the distribution was received are sold. Once a Fund shareholder's cost basis is reduced to zero, further distributions will be treated as capital gain, if the Fund shareholder holds shares of the Fund as capital assets. Because the Fund's distributions may consist of return of capital, the Fund may not be an appropriate investment for investors who do not want their principal investment in the Fund to decrease over time or who do not wish to receive return of capital in a given period.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | Income Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Income Risk. The Fund's income may decline when yields fall or written option premiums decline. This decline can occur because the Underlying Fund may subsequently invest in lower-yielding bonds as bonds in its portfolio mature, are near maturity or are called, bonds in the Underlying Fund's index are substituted, or the Underlying Fund otherwise needs to purchase additional bonds. Option premiums may fall due to changes in market conditions.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | Investment in Underlying Fund Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Investment in Underlying Fund Risk. The Fund invests in the Underlying Fund, so the Fund’s investment performance and risks are likely to be directly related to those of the Underlying Fund. The Fund’s NAV will change with changes in the value of the Underlying Fund and other assets that the Fund holds. The shares of the Underlying Fund may trade at a premium or discount to the Underlying Fund’s NAV. Investors in the Fund will indirectly bear the expenses charged by the Underlying Fund, and an investment in the Fund may entail more expenses than a direct investment in the Underlying Fund.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy 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 20+ Year Treasury Bond BuyWrite Strategy ETF | Tax Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Tax Risk. The tax rules and limitations that apply to the Fund will cause some or all of its income and gain to be taxable as ordinary income or at ordinary income rates, may accelerate its recognition of income and gain, and may defer its use of losses, all of which are expected to have negative tax consequences for the Fund and Fund investors. Because the assets comprising the Underlying Index and held by the Underlying Fund will not consist of stock, ordinary dividends from the Fund will not be eligible for the reduced rates applicable to “qualified dividend income” or eligible for the dividends-received deduction. The Fund expects that its ownership of shares of the Underlying Fund and sale of call options thereon generally will constitute “straddles” (offsetting positions with respect to personal property) under section 1092 of the Internal Revenue Code (“IRC”). The straddle rules generally do not apply if all the straddle’s offsetting positions consist of “qualified covered call options” and the stock to be purchased under the options, and the straddle is not part of a larger straddle. Unlike certain other funds that utilize covered call strategies, the Fund does not anticipate that this exception will be available because, as a general matter, the call options it writes are not expected to be treated as “qualified covered call options.” The straddle rules usually will terminate the Fund’s holding periods for its shares of the Underlying Fund that become part of a straddle before the long-term capital gain holding period (more than one year) has been reached, which is expected to eliminate the Fund’s ability to recognize long-term capital gains from a sale or other disposition of such shares. The straddle rules also usually will defer recognition of realized losses and require the capitalization of certain interest expenses and carrying charges. Similarly, “wash sale” rules may apply to defer the recognition of loss by the Fund from the disposition of stock or securities at a loss in a case in which identical or substantially identical stock or securities (or an option to acquire such property) is or has been acquired within a prescribed period. As a result of the foregoing, an investor may be subject to significantly greater amounts of tax as a result of the investment than would apply to an investment in a fund engaged in a different investment strategy.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy 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. To the extent that the Fund seeks to achieve its investment objective through investments in the Underlying Fund, the Fund may experience increased tracking error as compared to investing directly in the securities or other assets included in the underlying index of the Underlying Fund. A Fund that tracks an index with exposure to swaps, options, futures and/or other derivatives may experience higher tracking error than ETFs that do not track such indexes.
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| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Management Fees | rr_ManagementFeesOverAssets | 0.20% | [1] | ||||||||||||
| Distribution and Service (12b-1) Fees | rr_DistributionAndService12b1FeesOverAssets | none | [1] | ||||||||||||
| Other Expenses | rr_OtherExpensesOverAssets | none | [1] | ||||||||||||
| Acquired Fund Fees and Expenses | rr_AcquiredFundFeesAndExpensesOverAssets | 0.15% | [1] | ||||||||||||
| Total Annual Fund Operating Expenses | rr_ExpensesOverAssets | 0.35% | [1] | ||||||||||||
| 1 Year | rr_ExpenseExampleYear01 | $ 36 | |||||||||||||
| 3 Years | rr_ExpenseExampleYear03 | 113 | |||||||||||||
| 5 Years | rr_ExpenseExampleYear05 | 197 | |||||||||||||
| 10 Years | rr_ExpenseExampleYear10 | $ 443 | |||||||||||||
| 2023 | rr_AnnualReturn2023 | 0.75% | |||||||||||||
| 2024 | rr_AnnualReturn2024 | (2.12%) | |||||||||||||
| Highest Quarterly Return, Label | rr_HighestQuarterlyReturnLabel | Best Quarter | |||||||||||||
| Highest Quarterly Return, Date | rr_BarChartHighestQuarterlyReturnDate | Mar. 31, 2023 | |||||||||||||
| Highest Quarterly Return | rr_BarChartHighestQuarterlyReturn | 9.11% | |||||||||||||
| Lowest Quarterly Return, Label | rr_LowestQuarterlyReturnLabel | Worst Quarter | |||||||||||||
| Lowest Quarterly Return, Date | rr_BarChartLowestQuarterlyReturnDate | Sep. 30, 2023 | |||||||||||||
| Lowest Quarterly Return | rr_BarChartLowestQuarterlyReturn | (10.84%) | |||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | (2.12%) | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | (5.97%) | |||||||||||||
| Inception Date | rr_AverageAnnualReturnInceptionDate | Aug. 18, 2022 | |||||||||||||
| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | Return After Taxes on Distributions | iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | (2.66%) | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | (9.98%) | |||||||||||||
| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | Return After Taxes on Distributions and Sale of Fund Shares | iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | (1.25%) | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | (6.01%) | |||||||||||||
| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | ICE BofA US Broad Market Index (Returns do not reflect deductions for fees, expenses or taxes) | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 1.47% | [2] | ||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | 1.05% | [2] | ||||||||||||
| iShares 20+ Year Treasury Bond BuyWrite Strategy ETF | Cboe TLT 2% OTM BuyWrite Index (Returns do not reflect deductions for fees, expenses or taxes) | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | (1.12%) | |||||||||||||
| Since Fund Inception | rr_AverageAnnualReturnSinceInception | (5.19%) | |||||||||||||
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