| Label | Element | Value | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| iShares Short Duration Bond Active ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk/Return [Heading] | rr_RiskReturnHeading | iSHARES® SHORT DURATION BOND ACTIVE ETF Ticker: NEARStock Exchange: Cboe BZX | |||||||||||||
| Objective [Heading] | rr_ObjectiveHeading | Investment Objective | |||||||||||||
| Objective, Primary [Text Block] | rr_ObjectivePrimaryTextBlock | The iShares Short Duration Bond Active ETF (the “Fund”) seeks total return in excess of the reference benchmark.
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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 U.S. ETF 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 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”). 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 funds advised by BFA, or its affiliates, through February 28, 2030. The contractual waiver may be terminated prior to February 28, 2030 only upon written agreement of the Trust and BFA. 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 | |||||||||||||
| Fee Waiver or Reimbursement over Assets, Date of Termination | rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination | February 28, 2030 | |||||||||||||
| 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 164% of the average value of its portfolio. | |||||||||||||
| Portfolio Turnover, Rate | rr_PortfolioTurnoverRate | 164.00% | |||||||||||||
| 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 achieve its investment objective by investing, under normal circumstances, at least 80% of its net assets in a portfolio of U.S. dollar-denominated investment-grade fixed-income securities. The Fund's reference benchmark is the Bloomberg U.S. 1-3 Year Government/Credit Bond Index, which measures the performance of U.S. dollar-denominated, government, government-related and corporate securities with remaining maturity between one and three years. The Fund primarily invests in investment-grade fixed-income securities that are rated BBB- or higher by S&P Global Ratings and/or Fitch Ratings, Inc. (“Fitch”), or Baa3 or higher by Moody’s Investors Service, Inc. (“Moody's”), or, if unrated, determined by the Fund's management team to be of equivalent quality. The Fund primarily invests in fixed- and floating-rate securities of varying maturities, such as corporate and government bonds, agency securities, instruments of non-U.S. issuers, privately issued securities, asset-backed securities (“ABS”) and mortgage-backed securities (“MBS”), structured securities, municipal bonds, repurchase agreements, money market instruments and investment companies. The Fund invests in securities issued by financial institutions such as banks, broker-dealers and insurance companies. The Fund may enter into to-be-announced transactions (“TBA transactions”) on a regular basis with respect to the percentage of the portfolio (if any) that consists of mortgage-backed pass-through securities. BFA or its affiliates may advise the money market funds and investment companies in which the Fund may invest. Under normal circumstances, the effective duration of the Fund’s portfolio is expected to be three years or less, as calculated by the Fund’s management team. Effective duration is a measure of the Fund’s price sensitivity to changes in yields or interest rates; however, investors should be aware that effective duration is not an exact measurement and may not reliably predict a particular security’s price sensitivity to changes in yield or interest rates. The Fund may buy or sell options or futures on a security or an index of securities, or enter into credit default swaps and interest rate or foreign currency transactions, including swaps (collectively, commonly known as derivatives). The Fund may use derivatives to hedge its investments or to seek to enhance returns. The Fund is an actively managed exchange-traded fund (“ETF”) that does not seek to replicate the performance of a specified index. The Fund may have a higher degree of portfolio turnover than funds that seek to replicate the performance of an index. The Fund is not a money market fund and does not seek to maintain a stable net asset value of $1.00 per share. Please see the Fund’s Statement of Additional Information (“SAI”) for further information. The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of the collateral received).
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| Risk [Heading] | rr_RiskHeading | Summary of Principal Risks | |||||||||||||
| Bar Chart and Performance Table [Heading] | rr_BarChartAndPerformanceTableHeading | Performance Information | |||||||||||||
| Performance Narrative [Text Block] | rr_PerformanceNarrativeTextBlock | Effective November 1, 2023, the Fund changed its name, investment objective and investment strategies. Performance for the periods prior to November 1, 2023 shown below is based on the investment objective and investment strategies utilized by the Fund under the name “BlackRock Short Maturity Bond ETF.” From November 1, 2023 through October 9, 2024, the Fund operated under the name “BlackRock Short Duration Bond ETF.” 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 an additional index that Fund management believes more closely reflects the investment strategy of the Fund. 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. | |||||||||||||
| 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 Short Duration Bond Active 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 Short Duration Bond Active 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 Short Duration Bond Active 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 Short Duration Bond Active ETF | Risk of Investing in the US [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 Short Duration Bond Active 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 Short Duration Bond Active ETF | Management Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Management Risk. The Fund is subject to management risk, which is the risk that the investment process, techniques, models and/or risk analyses applied by BFA will not produce the desired results. The securities or other assets selected by BFA may result in returns that are inconsistent with the Fund’s investment objective, and the Fund may underperform the market or any relevant benchmark. In addition, legislative, regulatory, or tax developments may affect the investment techniques available to BFA in connection with managing the Fund and may adversely affect the ability of the Fund to achieve its investment objective.
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| iShares Short Duration Bond Active ETF | Asset Backed and Mortgage Backed Securities Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Asset-Backed and Mortgage-Backed Securities Risk. ABS and MBS (residential and commercial) represent interests in “pools” of mortgages or other assets, including consumer loans or receivables held in trust. ABS and MBS are subject to credit, interest rate, call, extension, valuation and liquidity risk. These securities, in most cases, are not backed by the full faith and credit of the U.S. government and are subject to the risk of default on the underlying asset or mortgage, particularly during periods of economic downturn. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain ABS and MBS.
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| iShares Short Duration Bond Active ETF | Asset Class Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Asset Class Risk. The securities and other assets in the Fund’s portfolio may underperform in comparison to financial markets generally, a particular financial market, an index, or other asset classes.
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| iShares Short Duration Bond Active 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 Short Duration Bond Active 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.
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| iShares Short Duration Bond Active ETF | Cash Transactions Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Cash Transactions Risk. The Fund may effect part or all of its creations and redemptions for cash, rather than in-kind securities. As a result, the Fund may have to sell portfolio securities at inopportune times in order to obtain the cash needed to meet redemption orders. This may cause the Fund to sell a security and recognize a capital gain or loss that might not have been incurred if it had made a redemption in-kind. The use of cash creations and redemptions may also cause the Fund’s shares to trade in the market at wider bid-ask spreads or greater premiums or discounts to the Fund’s NAV.
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| iShares Short Duration Bond Active 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 Short Duration Bond Active 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, 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 Short Duration Bond Active 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 Short Duration Bond Active ETF | Extension Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Extension Risk. During periods of rising interest rates, certain debt obligations may be paid off substantially more slowly than originally anticipated and the value of those securities may fall sharply, resulting in a decline in the Fund’s income and potentially in the value of the Fund’s investments.
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| iShares Short Duration Bond Active ETF | Financial Companies Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Financial Companies Risk. Financial services companies are subject to extensive governmental regulation and intervention, which may adversely affect their profitability, the scope of their activities, the prices they can charge, the amount of capital and liquid assets they must maintain and their size, among other things. Financial services companies also may be significantly affected by, among other things, interest rates, economic conditions, volatility in financial markets, credit rating downgrades, adverse public perception, exposure concentration and counterparty risk.
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| iShares Short Duration Bond Active ETF | Floating Rate Securities Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Floating Rate Securities Risk. Securities with floating or variable interest rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value if their coupon rates do not reset as high, or as quickly, as comparable market interest rates, and generally carry lower yields than fixed securities of the same maturity. Although floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to credit risk and default risk, which could impair their value.
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| iShares Short Duration Bond Active ETF | Futures Contract Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Futures Contract Risk. Futures contracts may involve risks different from, and possibly greater than, the risks associated with investing directly in the underlying assets. Swaps or other derivatives on futures contracts also may be adversely impacted by these risks. The primary risks of futures contracts include: (i) an imperfect correlation between the value of the futures contract and that of the underlying asset; (ii) resale restrictions or the lack of a liquid secondary market and the resulting inability to close a futures contract when desired; (iii) losses from unanticipated market movements, which are potentially unlimited; (iv) BFA’s inability to predict correctly the direction of the prices of futures contracts and other financial and economic factors; (v) a counterparty’s default in the performance of its obligations; (vi) the obligation to make daily cash payments to maintain the required margin for the futures contract; and (vi) the possibility that a failure to close a position may result in delivery of an illiquid commodity to the Fund. As futures contracts approach expiration, they may be “rolled” (i.e., replaced by similar contracts with a later expiration to maintain exposure to the underlying asset), which involves additional risks. In certain market conditions, the sale price of a near-term month contract can be lower than the purchase price of a longer-term contract, resulting in a cost to “roll” the futures contract.
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| iShares Short Duration Bond Active ETF | High Portfolio Turnover Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | High Portfolio Turnover Risk. High portfolio turnover is considered by the Fund to mean turnover of greater than 100% annually. Portfolio turnover (i.e., the sale of securities or other assets and reinvestment in other securities or assets) generally involves transaction costs to the Fund, including brokerage commissions, dealer mark-ups and other costs. In addition, the sale of securities by the Fund may result in the realization of taxable capital gains, including short-term capital gains. Higher portfolio turnover may cause the Fund to incur additional transaction costs, which have the effect of reducing the Fund’s investment return, and may result in different tax consequences for shareholders compared to a fund with lower portfolio turnover.
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| iShares Short Duration Bond Active 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 Short Duration Bond Active ETF | Income Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Income Risk. The Fund’s income may decline when interest rates fall because the Fund may hold a significant portion of short duration securities and/or securities that have floating or variable interest rates. The Fund’s income may decline because the Fund invests in lower yielding bonds, and as the bonds in its portfolio mature, are near maturity or are called, the Fund needs to purchase additional bonds.
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| iShares Short Duration Bond Active 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 Short Duration Bond Active 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 Short Duration Bond Active 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 Short Duration Bond Active 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.
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| iShares Short Duration Bond Active ETF | Not a Money Market Fund [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Not a Money Market Fund. The Fund is not a money market fund and is not subject to the strict rules that govern the quality, maturity, liquidity and other features of securities that money market funds may purchase. Under normal circumstances, the Fund’s investments may be more susceptible than a money market fund is to credit risk, interest rate risk, valuation risk and other risks relevant to the Fund’s investments. The Fund does not seek to maintain a stable net asset value of $1.00 per share.
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| iShares Short Duration Bond Active 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 Short Duration Bond Active ETF | Prepayment Risks [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | 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 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.
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| iShares Short Duration Bond Active ETF | Privately Issued Securities Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Privately Issued Securities Risk. Privately issued securities are securities that have not been registered under the Securities Act of 1933, as amended (the “1933 Act”). Such securities typically are subject to legal restrictions on resale and generally are not traded in established public markets. As a result, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities, may be subject to wide fluctuations in value and may have higher transaction costs. There can be no assurance that a trading market will exist at any time for any particular privately issued security. Difficulty in selling such securities at a desirable time or price may result in a loss to the Fund.
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| iShares Short Duration Bond Active ETF | Repurchase Agreement Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Repurchase Agreement Risk. A repurchase agreement is an instrument under which the purchaser (i.e., the Fund) acquires a security and the seller agrees, at the time of the sale, to repurchase the security at a mutually agreed upon time and price. Repurchase agreements may be construed to be collateralized loans by the purchaser to the seller secured by the securities transferred to the purchaser. If a repurchase agreement is construed to be a collateralized loan, the underlying securities will not be considered to be owned by the Fund but only to constitute collateral for the seller’s obligation to pay the repurchase price. If the seller defaults on its obligation under the agreement, the Fund may suffer delays and incur costs or lose money in exercising its rights under the agreement. If the seller fails to repurchase the security and the market value of the security declines, the Fund may lose money.
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| iShares Short Duration Bond Active ETF | Risk of Swap Agreements [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Risk of Swap Agreements. A swap is a two-party contract that generally obligates each counterparty to exchange periodic payments based on a pre-determined underlying investment or notional amount and to exchange collateral to secure the obligations of each counterparty. Swaps may be leveraged and are subject to counterparty risk, credit risk and pricing risk. Swaps may be subject to illiquidity risk, and it may not be possible for the Fund to liquidate a swap position at an advantageous time or price, which may result in significant losses.
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| iShares Short Duration Bond Active ETF | Securities Lending Risk [Member] | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Risk [Text Block] | rr_RiskTextBlock | Securities Lending Risk. The Fund may engage in securities lending. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money in the event of a decline in the value of collateral provided for loaned securities or a decline in the value of any investments made with cash collateral. These events could also trigger adverse tax consequences for the Fund.
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| iShares Short Duration Bond Active 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. 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 Short Duration Bond Active 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 Short Duration Bond Active ETF | iShares Short Duration Bond Active ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| Management Fees | rr_ManagementFeesOverAssets | 0.25% | [1] | ||||||||||||
| Distribution and Service (12b-1) Fees | rr_DistributionAndService12b1FeesOverAssets | none | [1] | ||||||||||||
| Other Expenses | rr_OtherExpensesOverAssets | none | [1],[2] | ||||||||||||
| Acquired Fund Fees and Expenses | rr_AcquiredFundFeesAndExpensesOverAssets | none | [1],[2] | ||||||||||||
| Total Annual Fund Operating Expenses | rr_ExpensesOverAssets | 0.25% | [1] | ||||||||||||
| Fee Waiver and/or Expense Reimbursement | rr_FeeWaiverOrReimbursementOverAssets | none | [1],[2] | ||||||||||||
| Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement | rr_NetExpensesOverAssets | 0.25% | [1] | ||||||||||||
| 1 Year | rr_ExpenseExampleYear01 | $ 26 | |||||||||||||
| 3 Years | rr_ExpenseExampleYear03 | 80 | |||||||||||||
| 5 Years | rr_ExpenseExampleYear05 | 141 | |||||||||||||
| 10 Years | rr_ExpenseExampleYear10 | $ 318 | |||||||||||||
| 2015 | rr_AnnualReturn2015 | 0.69% | |||||||||||||
| 2016 | rr_AnnualReturn2016 | 1.42% | |||||||||||||
| 2017 | rr_AnnualReturn2017 | 1.55% | |||||||||||||
| 2018 | rr_AnnualReturn2018 | 1.71% | |||||||||||||
| 2019 | rr_AnnualReturn2019 | 3.47% | |||||||||||||
| 2020 | rr_AnnualReturn2020 | 1.43% | |||||||||||||
| 2021 | rr_AnnualReturn2021 | 0.34% | |||||||||||||
| 2022 | rr_AnnualReturn2022 | 0.36% | |||||||||||||
| 2023 | rr_AnnualReturn2023 | 7.33% | |||||||||||||
| 2024 | rr_AnnualReturn2024 | 5.04% | |||||||||||||
| Highest Quarterly Return, Label | rr_HighestQuarterlyReturnLabel | Best Quarter | |||||||||||||
| Highest Quarterly Return, Date | rr_BarChartHighestQuarterlyReturnDate | Jun. 30, 2020 | |||||||||||||
| Highest Quarterly Return | rr_BarChartHighestQuarterlyReturn | 3.59% | |||||||||||||
| Lowest Quarterly Return, Label | rr_LowestQuarterlyReturnLabel | Worst Quarter | |||||||||||||
| Lowest Quarterly Return, Date | rr_BarChartLowestQuarterlyReturnDate | Mar. 31, 2020 | |||||||||||||
| Lowest Quarterly Return | rr_BarChartLowestQuarterlyReturn | (3.06%) | |||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 5.04% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 2.86% | |||||||||||||
| Ten Years | rr_AverageAnnualReturnYear10 | 2.31% | |||||||||||||
| Inception Date | rr_AverageAnnualReturnInceptionDate | Sep. 25, 2013 | |||||||||||||
| iShares Short Duration Bond Active ETF | Return After Taxes on Distributions | iShares Short Duration Bond Active ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 2.92% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 1.72% | |||||||||||||
| Ten Years | rr_AverageAnnualReturnYear10 | 1.39% | |||||||||||||
| iShares Short Duration Bond Active ETF | Return After Taxes on Distributions and Sale of Fund Shares | iShares Short Duration Bond Active ETF | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 2.96% | |||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 1.70% | |||||||||||||
| Ten Years | rr_AverageAnnualReturnYear10 | 1.37% | |||||||||||||
| iShares Short Duration Bond Active ETF | Bloomberg U.S. Universal Index (Returns do not reflect deductions for fees, expenses or taxes) | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 2.04% | [3] | ||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 0.06% | [3] | ||||||||||||
| Ten Years | rr_AverageAnnualReturnYear10 | 1.73% | [3] | ||||||||||||
| iShares Short Duration Bond Active ETF | Bloomberg U.S. 1-3 Year Government/Credit Bond Index (Returns do not reflect deductions for fees, expenses or taxes) | |||||||||||||||
| Risk/Return: | rr_RiskReturnAbstract | ||||||||||||||
| One Year | rr_AverageAnnualReturnYear01 | 4.36% | [4] | ||||||||||||
| Five Years | rr_AverageAnnualReturnYear05 | 1.58% | [4] | ||||||||||||
| Ten Years | rr_AverageAnnualReturnYear10 | 1.63% | [4] | ||||||||||||
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