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iShares iBonds Dec 2029 Term Corporate ETF  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading iSHARES® iBONDS® DEC 2029 TERM CORPORATE ETF Ticker: IBDUStock Exchange: NYSE Arca
Objective [Heading] rr_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The iShares iBonds Dec 2029 Term Corporate ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, investment-grade corporate bonds maturing in 2029.
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”). 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 the termination date of the Fund, on or about December 15, 2029. The contractual waiver may be terminated prior to the Fund's termination only upon the 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.
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 December 15, 2029
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 21% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 21.00%
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.Fund expenses (and any applicable waivers) are calculated only through December 15, 2029 because the Fund is scheduled to cease operations and liquidate by that date. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading] rr_StrategyHeading Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg December 2029 Maturity Corporate Index (the “Underlying Index”). The Fund may also invest in U.S. government securities, short-term paper, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates.
The Fund is a term fund that will terminate on or about December 15, 2029, at which time it will distribute its remaining net assets to shareholders pursuant to a plan of liquidation. The Fund does not seek to return any predetermined amount at maturity or in periodic distributions. The Underlying Index is composed of U.S. dollar-denominated, taxable, investment-grade (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature between January 1, 2029 and December 15, 2029, inclusive. As of October 31, 2024, a significant portion of the Underlying Index is represented by securities of companies in the consumer goods and services and financials industries or sectors. The components of the Underlying Index are likely to change over time.
The Underlying Index consists of U.S. dollar-denominated, investment-grade securities publicly issued by U.S. and non-U.S. corporate issuers that have $300 million or more of outstanding face value at the time of inclusion. The non-U.S. corporate issuers included in the Underlying Index consist primarily of corporate bonds issued by companies domiciled in developed countries. The Fund will invest in non-U.S. issuers to the extent necessary for it to track the Underlying Index. Each bond included in the Underlying Index must be registered with the SEC, have been exempt from registration at issuance, or have been offered pursuant to Rule 144A under the Securities Act of 1933, as amended (the “1933 Act”), with registration rights. Further, the securities in the Underlying Index must be denominated in U.S. dollars and have a fixed-rate, although they can carry a coupon that steps-up or changes according to a predetermined schedule. In addition, to be included in the Underlying Index, securities that are rated by all three of the rating agencies named below must be rated “investment-grade” by at least two of the three rating agencies, which is defined as Baa3 or higher by Moody’s Investors Service, Inc. or BBB- or higher by S&P Global Ratings or Fitch Ratings, Inc. When ratings from only two of the three rating agencies are available, the lower rating is used to determine eligibility. Securities with a rating from only one of the three ratings agencies must be rated investment-grade in order to be included in the Underlying Index. In cases where ratings are not available, other sources may be used to classify securities by investment quality.
The Underlying Index is constructed with the following methodology. The parent index, the Bloomberg U.S. Corporate
Index (the “Parent Index”), representing U.S. dollar-denominated, taxable, investment-grade corporate bonds, is stripped of securities maturing outside of the maturity range described above. During the final two years of the Underlying Index, bonds that mature in 2029, but had not been eligible for inclusion in the Parent Index due to being within one year of maturity, will be eligible for inclusion in the Underlying Index until such bonds reach maturity. Securities are then market-cap weighted within the Underlying Index, with a 3% cap typically imposed on any one issuer, and a pro rata distribution of any excess weight across the remaining issuers in the Underlying Index. In the event a 3% cap is not possible due to lack of issuers, the cap will be increased in 0.50% increments until the Underlying Index can be calculated.
The securities in the Underlying Index are updated on the last calendar day of each month until six months prior to maturity. The last rebalance date will be on June 30, 2029. During this final six month period, the Underlying Index will no longer be updated or rebalanced, except to remove securities which are downgraded to below investment-grade per the eligibility criteria described above. Additionally, during this period, existing bond weights will be allowed to float based on changes in market value.
When a bond that is included in the Underlying Index matures, its maturity value will be represented in the Underlying Index by cash throughout the remaining life of the Underlying Index.
The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The Fund does not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the Fund holds cash equivalent instruments consistent with its investment objective) and is not designed to provide protection against inflation.
BFA uses an indexing approach to try to achieve the Fund’s investment objective. The Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.
Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.
BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration (i.e., a security's price sensitivity to a change in interest rates), maturity or credit ratings and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the securities in the Underlying Index.
The Fund will invest at least 80% of its assets in the component instruments of the Underlying Index, and (except during the last twelve months of the Fund’s operations) the Fund will invest at least 90% of its assets in fixed income securities of the types included in the Underlying Index that BFA believes will help the
Fund track the Underlying Index. The Fund will invest no more than 10% of its assets in futures, options and swaps contracts that BFA believes will help the Fund track the Underlying Index as well as in fixed income securities other than the types included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. Cash and cash equivalent investments associated with a derivative position will be treated as part of that position for the purposes of calculating the percentage of investments included in the Underlying Index.
In the last six months of operation, as the bonds held by the Fund mature, the proceeds may not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By fifteen days prior to maturity, the Underlying Index is expected to consist almost entirely of cash and cash equivalents. On or around this date, the Fund will wind up and terminate. After appropriate provision is made for any Fund liabilities, its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund's termination was approved by a majority of the Trust's Board of Trustees (the “Board”) and does not require additional approval by Fund shareholders. The Board may extend the termination date if a majority of the Board determines the extension to be in the best interest of the Fund.
The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. To the extent that the Fund invests in money market or similar funds, it will incur the fees and expenses of such funds.
The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that converts fund assets to conservative investments over time.
The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of any collateral received).
The Underlying Index is sponsored by Bloomberg, which is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index.
Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry.
Strategy Portfolio Concentration [Text] rr_StrategyPortfolioConcentration Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities), repurchase agreements collateralized by U.S. government securities, and securities of state or municipal governments and their political subdivisions are not considered to be issued by members of any industry.
Risk [Heading] rr_RiskHeading Summary of Principal Risks
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance Information
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The performance information below illustrates how the Fund’s performance has varied over different periods and provides some indication of the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table compares the Fund’s performance to that of an appropriate broad-based securities market index and the Underlying Index. Fund returns assume the reinvestment of any dividends and distributions. The Fund’s returns reflect the impact of any agreements to waive or reimburse expenses, which would reduce performance if not in effect. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information, including the Fund’s current NAV, may be obtained by visiting www.iShares.com or by calling 1-800-iShares (1-800-474-2737) (toll free).
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
 
Return (%)
Period Ended
During the periods shown in the chart:
Best Quarter
11.34%
June 30, 2020
Worst Quarter
-6.41%
March 31, 2022
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.
iShares iBonds Dec 2029 Term Corporate ETF | Risk Lose Money [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate ETF | Index Related Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Index-Related Risk. The Index Provider may rely on various sources of information to assess the criteria of components of the Underlying Index, including information that may be based on assumptions and estimates. Neither the Fund nor BFA can offer assurances that the Index Provider’s methodology or sources of information will provide an accurate assessment of included components or will result in the Fund meeting its investment objective. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur, and the Index Provider may not identify or correct them promptly or at all, which may have an adverse impact on the Fund and its shareholders. Unusual market conditions or other unforeseen circumstances (such as natural disasters, political unrest or war) may impact the Index Provider or a third-party data provider and could cause the Index Provider to postpone a scheduled rebalance. This could cause the Underlying Index to vary from its normal or expected composition.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate ETF | Consumer Goods and Services Companies Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Consumer Goods and Services Companies Risk. Consumer goods and services companies (“consumer companies”) face risks related to changes in consumer preferences and disposable income, commodity prices, government regulation, supply chain disruptions, damage to brand or reputation, economic slowdown and labor shortages, among other things.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate ETF | Declining Yield Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Declining Yield Risk. During the twelve months prior to the Fund’s planned termination date, the Fund’s yield will generally tend to move toward prevailing money market rates and may be lower than the yields of the bonds previously held by the Fund and lower than prevailing yields for bonds in the market.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate ETF | Fluctuation of Yield and Liquidation Amount Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Fluctuation of Yield and Liquidation Amount Risk. The Fund, unlike a direct investment in a bond that has a level coupon payment and a fixed payment at maturity, will make distributions of income that vary over time. It is expected that an investment in the Fund, if held through maturity, will produce aggregate returns comparable to a direct investment in a group of bonds of similar credit quality and maturity. Unlike a direct investment in bonds, the breakdown of returns between Fund distributions and liquidation proceeds are not predictable at the time of your investment. For example, at times during the Fund's existence it may make distributions at a greater (or lesser) rate than the coupon payments received on the Fund's portfolio, which would result in the Fund returning a lesser (or greater) amount on liquidation than would otherwise be the case. The rate of Fund distribution payments may adversely affect the tax characterization of your returns from an investment in the Fund relative to a direct investment in bonds. If the amount you receive as liquidation proceeds upon the Fund's termination is higher or lower than your cost basis, you may experience a gain or loss for tax purposes.
iShares iBonds Dec 2029 Term Corporate ETF | Income Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Income Risk. The Fund's income may decline if interest rates fall. This decline in income can occur because the Fund may subsequently invest in lower-yielding bonds as bonds in its portfolio mature, are near maturity or are called, bonds in the Underlying Index are substituted, or the Fund otherwise needs to purchase additional bonds. As the Fund does not seek to return any predetermined amount at maturity or in periodic distributions, the amount of income generated by the Fund may vary during its term. In addition, the Fund's income is expected to decline in the months leading up to its maturity date because its portfolio will increasingly consist of cash and cash equivalents.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate ETF | Reinvestment Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Reinvestment Risk. The Fund may invest a portion of its assets in short-term fixed-income instruments and, as a result, may be adversely affected if interest rates fall because it may have to invest in lower-yielding instruments as bonds in the Fund's portfolio mature.
iShares iBonds Dec 2029 Term Corporate ETF | Reliance on Trading Partners Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Reliance on Trading Partners Risk. The Fund invests in countries or regions whose economies are heavily dependent upon trading with key partners. Any reduction in this trading may have an adverse impact on the Fund's investments.
iShares iBonds Dec 2029 Term Corporate ETF | Risk of Investing in China [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Risk of Investing in China. Investments in Chinese securities, including certain Hong Kong-listed and U.S.-listed securities, subject the Fund to risks specific to China. China may be subject to considerable degrees of economic, political and social instability. China is an emerging market and demonstrates significantly higher volatility from time to time in comparison to developed markets. Over the last few decades, the Chinese government has undertaken reform of economic and market practices and has expanded the sphere of private ownership of property in China. However, Chinese markets generally continue to experience inefficiency, volatility and pricing anomalies resulting from governmental influence, a lack of publicly available information and/or political and social instability. Chinese companies are also subject to the risk that Chinese authorities can intervene in their operations and structure. Internal social unrest or confrontations with neighboring countries, including military conflicts in response to such events, may also disrupt economic development in China and result in a greater risk of currency fluctuations, currency non-convertibility, interest rate fluctuations and higher rates of inflation.
China has experienced security concerns, such as terrorism and strained international relations. Additionally, China is alleged to have participated in state-sponsored cyberattacks against foreign companies and foreign governments. Actual and threatened responses to such activity and strained international relations, including purchasing restrictions, sanctions, tariffs or cyberattacks on the Chinese government or Chinese companies, may impact China’s economy and Chinese issuers of securities in which the Fund invests. Incidents involving China's or the region's security may cause uncertainty in Chinese markets and may adversely affect the Chinese economy and the Fund's investments. Export growth continues to be a major driver of China's rapid economic growth. Reduction in spending on Chinese products and services, supply chain diversification, institution of
additional tariffs or other trade barriers (including as a result of heightened trade tensions or a trade war between China and the U.S. or in response to actual or alleged Chinese cyber activity) or a downturn in any of the economies of China's key trading partners may have an adverse impact on the Chinese economy. The Underlying Index may include companies that are subject to economic or trade restrictions (but not investment restrictions) imposed by the U.S. or other governments due to national security, human rights or other concerns of such government. So long as these restrictions do not include restrictions on investments, the Fund is generally expected to invest in such companies, consistent with its objective to track the performance of the Underlying Index.
Chinese companies, including Chinese companies that are listed on U.S. exchanges, are not subject to the same degree of regulatory requirements, accounting standards or auditor oversight as companies in more developed countries. As a result, information about Chinese securities in which the Fund invests may be less reliable or complete. Chinese companies with securities listed on U.S. exchanges may be delisted if they do not meet U.S. accounting standards and auditor oversight requirements, which would significantly decrease the liquidity and value of the securities. There may be significant obstacles to obtaining information necessary for investigations into or litigation against Chinese companies, and investors may have limited legal remedies. The Fund does not select investments based on investor protection considerations.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate 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.
iShares iBonds Dec 2029 Term Corporate ETF | Valuation Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Valuation Risk. The price that the Fund could receive upon the sale (or other disposition) of a security or other asset may differ from the Fund’s valuation of the security or other asset, particularly for securities or other assets that trade in low volume or volatile markets or that are valued using a fair value methodology. The price received by the Fund also may differ from the value used by the Underlying Index. In addition, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when investors are not able to purchase or sell Fund shares. Authorized Participants that create or redeem Fund shares on days when the Fund is holding fair-valued securities or other assets may receive fewer or more shares, or lower or higher redemption proceeds, than they would have received had the securities or other assets not been fair valued or been valued using a different methodology. The ability to value investments may be impacted by technological issues or errors by pricing services or other third-party service providers.
iShares iBonds Dec 2029 Term Corporate ETF | Risk of Investing in the China Bond Market [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Risk of Investing in the China Bond Market. The Fund invests directly in the domestic bond market in the People’s Republic of China (“China” or the “PRC”) (the “China Interbank Bond Market”) through the Bond Connect trading channel. All bonds traded through Bond Connect are registered in the name of the PRC’s Central Moneymarkets Unit (“CMU”), which holds such bonds as a nominee owner. The precise nature and rights of the Fund as the beneficial owner of bonds traded in the China Interbank Bond Market through CMU as nominee are relatively new and untested areas of PRC law, and the exact nature of the Fund’s remedies and methods of enforcement of its rights and interests under PRC law are uncertain.
Market volatility and potential lack of liquidity due to low trading volume of certain bonds in the China Interbank Bond Market may result in the prices of certain bonds fluctuating significantly. Also, the systems used to trade through Bond Connect may not function as expected. Trading through Bond Connect is also subject to regulatory risks, including laws and regulations that are subject to change. There can be no assurance that Bond Connect or its features or systems will not be materially altered, suspended, discontinued or abolished. The Fund may be subject to additional taxation if certain tax exemptions under PRC tax regulations are withdrawn or amended. Any taxes arising from or to the Fund may be directly borne by, or indirectly passed on to, the Fund, which may substantially impact its NAV. Investing through Bond Connect subjects the Fund to currency risk, to the extent that currency rates used for Bond Connect are different than the rates used in the China Interbank Bond Market.
iShares iBonds Dec 2029 Term Corporate ETF | iShares iBonds Dec 2029 Term Corporate ETF  
Risk/Return: rr_RiskReturnAbstract  
Management Fees rr_ManagementFeesOverAssets 0.10% [1]
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none [1]
Other Expenses rr_OtherExpensesOverAssets none [1]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets none [1],[2]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.10% [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 0.10% [1]
1 Year rr_ExpenseExampleYear01 $ 10
3 Years rr_ExpenseExampleYear03 32
Maturity ist_ExpenseExampleMaturity $ 54
2020 rr_AnnualReturn2020 10.49%
2021 rr_AnnualReturn2021 (1.96%)
2022 rr_AnnualReturn2022 (13.05%)
2023 rr_AnnualReturn2023 8.51%
2024 rr_AnnualReturn2024 3.81%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 11.34%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2022
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (6.41%)
One Year rr_AverageAnnualReturnYear01 3.81%
Five Years rr_AverageAnnualReturnYear05 1.19%
Since Fund Inception rr_AverageAnnualReturnSinceInception 1.62%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 17, 2019
iShares iBonds Dec 2029 Term Corporate ETF | Return After Taxes on Distributions | iShares iBonds Dec 2029 Term Corporate ETF  
Risk/Return: rr_RiskReturnAbstract  
One Year rr_AverageAnnualReturnYear01 1.82%
Five Years rr_AverageAnnualReturnYear05 (0.21%)
Since Fund Inception rr_AverageAnnualReturnSinceInception 0.24%
iShares iBonds Dec 2029 Term Corporate ETF | Return After Taxes on Distributions and Sale of Fund Shares | iShares iBonds Dec 2029 Term Corporate ETF  
Risk/Return: rr_RiskReturnAbstract  
One Year rr_AverageAnnualReturnYear01 2.23%
Five Years rr_AverageAnnualReturnYear05 0.31%
Since Fund Inception rr_AverageAnnualReturnSinceInception 0.65%
iShares iBonds Dec 2029 Term Corporate 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]
Since Fund Inception rr_AverageAnnualReturnSinceInception 0.28% [3]
iShares iBonds Dec 2029 Term Corporate ETF | Bloomberg December 2029 Maturity Corporate Index (Returns do not reflect deductions for fees, expenses or taxes)  
Risk/Return: rr_RiskReturnAbstract  
One Year rr_AverageAnnualReturnYear01 3.72%
Five Years rr_AverageAnnualReturnYear05 1.27%
Since Fund Inception rr_AverageAnnualReturnSinceInception 1.66%
[1] Operating expenses paid by BFA under the Investment Advisory Agreement exclude Acquired Fund Fees and Expenses, if any.
[2] The amount rounded to 0.00%.
[3] The Fund has added this broad-based index in response to new regulatory requirements.