497

 

Allison Pristash 

State Street 

1 Lincoln Street 

Mail Stop SFC 0805 

Boston, MA 02111 

Tel +1 617 662 7031 

APristash@StateStreet.com 

July 14, 2020 

Securities and Exchange Commission 

100 F Street, N.E. 

Washington, DC 20549 

RE:iShares Trust (the “Registrant”) 

      Securities Act File No. 333-92935 

Investment Company Act File No. 811-09729 

Ladies and Gentlemen: 

On behalf of the Registrant and pursuant to Rule 497 under the Securities Act of 1933, as amended, attached for filing are exhibits containing interactive data format risk/return summary information that mirrors the risk/return summary information in the 497 filing, dated June 30, 2020 to the prospectuses for the following funds: 

iShares iBonds 2021 Term High Yield and Income ETF  

iShares iBonds 2022 Term High Yield and Income ETF 

iShares iBonds 2023 Term High Yield and Income ETF 

iShares iBonds 2024 Term High Yield and Income ETF 

iShares iBonds 2025 Term High Yield and Income ETF 

The purpose of this filing is to submit the 497 dated June 30, 2020 in XBRL.  

If you have any questions regarding this filing, please contact Benjamin Haskin of Willkie Farr & Gallagher LLP at (202) 303-1124. 

Very truly yours, 

/s/ Allison Pristash 

Allison Pristash 

cc:  Benjamin Haskin, Esq. 

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	497
Document Period End Date	dei_DocumentPeriodEndDate	Oct. 31, 2019
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Central Index Key	dei_EntityCentralIndexKey	0001100663
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Jun. 30, 2020
Document Effective Date	dei_DocumentEffectiveDate	Jun. 30, 2020
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
Entity Inv Company Type	dei_EntityInvCompanyType	N-1A

XML

Total

iShares iBonds 2021 Term High Yield and Income ETF

iSHARES® iBONDS® 2021 TERM HIGH YIELD AND INCOME ETF Ticker: IBHA                                 Stock Exchange: Cboe BZX

Investment Objective

The iShares iBonds 2021 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2021.

Fees and Expenses

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).

You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:

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

Annual Fund Operating Expenses	Management Fees	Distribution and Service (12b-1) Fees	Other Expenses		Acquired Fund Fees and Expenses		Total Annual Fund Operating Expenses	Fee Waiver		Total Annual Fund Operating Expenses After Fee Waiver
iShares iBonds 2021 Term High Yield and Income ETF | iShares iBonds 2021 Term High Yield and Income ETF	0.35%	none	none	[1]	none	[1],[2]	0.35%	none	[1],[2]	0.35%

Example.

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:

Expense Example	1 Year	Maturity
iShares iBonds 2021 Term High Yield and Income ETF | iShares iBonds 2021 Term High Yield and Income ETF | USD ($)	36	66

Portfolio Turnover.

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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 17% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2021 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2021, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2020 and before December 16, 2021. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services and consumer cyclical industries or sectors. The components of the Underlying Index are likely to change over time.

The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis.

The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest.

The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2021. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's^® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2021, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index.

The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index.

The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2021, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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.

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor.

Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund.

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

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.

Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests.

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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Consumer Cyclical Industry Risk. Consumer cyclical companies rely heavily on business cycles and economic conditions. Consumer cyclical companies may be adversely affected by domestic and international economic downturns, changes in exchange and interest rates, competition, consumers’ disposable income and preferences, social trends and marketing campaigns.

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.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Declining Yield Risk. During the six 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.

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.

High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.”

Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV.

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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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.

Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition.

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

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

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results.

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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.

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.

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

Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund.

Reinvestment Risk. The Fund 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.

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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk.

Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

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.

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

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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES.

Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.

Performance Information

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

[1] The amount rounded to 0.00%.

[2] 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, 2021. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
iShares iBonds 2021 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® iBONDS® 2021 TERM HIGH YIELD AND INCOME ETF Ticker: IBHA                                 Stock Exchange: Cboe BZX
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares iBonds 2021 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2021.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”). You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	December 15, 2021
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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 17% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	17.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2021 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2021, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2020 and before December 16, 2021. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services and consumer cyclical industries or sectors. The components of the Underlying Index are likely to change over time. The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis. The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest. The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2021. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2021, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index. The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2021, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor. Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. 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. Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests. 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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Consumer Cyclical Industry Risk. Consumer cyclical companies rely heavily on business cycles and economic conditions. Consumer cyclical companies may be adversely affected by domestic and international economic downturns, changes in exchange and interest rates, competition, consumers’ disposable income and preferences, social trends and marketing campaigns. 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. Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests. Declining Yield Risk. During the six 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. 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. High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.” Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV. 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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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. Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts. Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results. 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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. 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. Passive Investment Risk. The Fund is not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Reinvestment Risk. The Fund 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. 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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk. Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. 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. Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders. 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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES. Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
iShares iBonds 2021 Term High Yield and Income ETF | iShares iBonds 2021 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.35%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none	[1]
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.35%
Fee Waiver	rr_FeeWaiverOrReimbursementOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses After Fee Waiver	rr_NetExpensesOverAssets	0.35%
1 Year	rr_ExpenseExampleYear01	$ 36
Maturity	ist1_ExpenseExampleMaturity	$ 66

[1] The amount rounded to 0.00%.

[2] 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, 2021. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

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iShares iBonds 2022 Term High Yield and Income ETF

iSHARES® iBONDS® 2022 TERM HIGH YIELD AND INCOME ETF Ticker: IBHB                                 Stock Exchange: Cboe BZX

Investment Objective

The iShares iBonds 2022 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2022.

Fees and Expenses

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).

You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:

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

Annual Fund Operating Expenses	Management Fees	Distribution and Service (12b-1) Fees	Other Expenses		Acquired Fund Fees and Expenses		Total Annual Fund Operating Expenses	Fee Waiver		Total Annual Fund Operating Expenses After Fee Waiver
iShares iBonds 2022 Term High Yield and Income ETF | iShares iBonds 2022 Term High Yield and Income ETF	0.35%	none	none	[1]	none	[1],[2]	0.35%	none	[1],[2]	0.35%

Example.

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:

Expense Example	1 Year	Maturity
iShares iBonds 2022 Term High Yield and Income ETF | iShares iBonds 2022 Term High Yield and Income ETF | USD ($)	36	105

Portfolio Turnover.

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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 14% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2022 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2022, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2021 and before December 16, 2022. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services industry or sector. The components of the Underlying Index are likely to change over time.

The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis.

The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest.

The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2022. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's^® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2022, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index.

The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index.

The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2022, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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.

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor.

Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund.

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

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.

Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests.

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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Credit Risk. Debt issuers and other counterparties may be unable or unwilling to make timely interest and/or principal payments when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s 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.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Declining Yield Risk. During the six 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.

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.

High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.”

Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV.

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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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.

Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition.

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

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

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results.

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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.

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.

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

Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund.

Reinvestment Risk. The Fund 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.

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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk.

Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

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.

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

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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES.

Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.

Performance Information

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

[1] The amount rounded to 0.00%.

[2] 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, 2022. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
iShares iBonds 2022 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® iBONDS® 2022 TERM HIGH YIELD AND INCOME ETF Ticker: IBHB                                 Stock Exchange: Cboe BZX
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares iBonds 2022 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2022.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”). You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	December 15, 2022
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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 14% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	14.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2022 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2022, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2021 and before December 16, 2022. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services industry or sector. The components of the Underlying Index are likely to change over time. The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis. The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest. The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2022. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2022, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index. The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2022, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor. Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. 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. Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests. 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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Credit Risk. Debt issuers and other counterparties may be unable or unwilling to make timely interest and/or principal payments when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s 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. Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests. Declining Yield Risk. During the six 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. 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. High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.” Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV. 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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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. Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts. Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results. 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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. 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. Passive Investment Risk. The Fund is not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Reinvestment Risk. The Fund 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. 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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk. Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. 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. Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders. 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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES. Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
iShares iBonds 2022 Term High Yield and Income ETF | iShares iBonds 2022 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.35%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none	[1]
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.35%
Fee Waiver	rr_FeeWaiverOrReimbursementOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses After Fee Waiver	rr_NetExpensesOverAssets	0.35%
1 Year	rr_ExpenseExampleYear01	$ 36
Maturity	ist1_ExpenseExampleMaturity	$ 105

[1] The amount rounded to 0.00%.

[2] 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, 2022. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

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iShares iBonds 2023 Term High Yield and Income ETF

iSHARES® iBONDS® 2023 TERM HIGH YIELD AND INCOME ETF Ticker: IBHC                                 Stock Exchange: Cboe BZX

Investment Objective

The iShares iBonds 2023 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2023.

Fees and Expenses

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).

You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:

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

Annual Fund Operating Expenses	Management Fees	Distribution and Service (12b-1) Fees	Other Expenses		Acquired Fund Fees and Expenses		Total Annual Fund Operating Expenses	Fee Waiver		Total Annual Fund Operating Expenses After Fee Waiver
iShares iBonds 2023 Term High Yield and Income ETF | iShares iBonds 2023 Term High Yield and Income ETF	0.35%	none	none	[1]	none	[1],[2]	0.35%	none	[1],[2]	0.35%

Example.

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:

Expense Example	1 Year	3 Years
iShares iBonds 2023 Term High Yield and Income ETF | iShares iBonds 2023 Term High Yield and Income ETF | USD ($)	36	113

Portfolio Turnover.

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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 9% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2023 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2023, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2022 and before December 16, 2023. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services and consumer cyclical industries or sectors. The components of the Underlying Index are likely to change over time.

The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis.

The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest.

The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2023. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's^® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2023, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index.

The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index.

The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2023, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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.

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor.

Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund.

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

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.

Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests.

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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Consumer Cyclical Industry Risk. Consumer cyclical companies rely heavily on business cycles and economic conditions. Consumer cyclical companies may be adversely affected by domestic and international economic downturns, changes in exchange and interest rates, competition, consumers’ disposable income and preferences, social trends and marketing campaigns.

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.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Declining Yield Risk. During the six 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.

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.

High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.”

Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV.

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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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.

Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition.

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

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

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results.

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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.

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.

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

Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund.

Reinvestment Risk. The Fund 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.

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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk.

Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

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.

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

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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES.

Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.

Performance Information

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

[1] The amount rounded to 0.00%.

[2] 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, 2023. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
iShares iBonds 2023 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® iBONDS® 2023 TERM HIGH YIELD AND INCOME ETF Ticker: IBHC                                 Stock Exchange: Cboe BZX
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares iBonds 2023 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2023.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur “Acquired Fund Fees and Expenses.” Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”). You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	December 15, 2023
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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 9% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	9.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2023 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2023, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2022 and before December 16, 2023. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services and consumer cyclical industries or sectors. The components of the Underlying Index are likely to change over time. The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis. The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest. The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2023. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2023, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index. The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2023, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor. Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. 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. Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests. 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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Consumer Cyclical Industry Risk. Consumer cyclical companies rely heavily on business cycles and economic conditions. Consumer cyclical companies may be adversely affected by domestic and international economic downturns, changes in exchange and interest rates, competition, consumers’ disposable income and preferences, social trends and marketing campaigns. 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. Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests. Declining Yield Risk. During the six 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. 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. High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.” Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV. 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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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. Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts. Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results. 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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. 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. Passive Investment Risk. The Fund is not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Reinvestment Risk. The Fund 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. 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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk. Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. 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. Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders. 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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES. Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
iShares iBonds 2023 Term High Yield and Income ETF | iShares iBonds 2023 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.35%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none	[1]
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.35%
Fee Waiver	rr_FeeWaiverOrReimbursementOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses After Fee Waiver	rr_NetExpensesOverAssets	0.35%
1 Year	rr_ExpenseExampleYear01	$ 36
3 Years	rr_ExpenseExampleYear03	$ 113

[1] The amount rounded to 0.00%.

[2] 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, 2023. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

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iShares iBonds 2024 Term High Yield and Income ETF

iSHARES® iBONDS® 2024 TERM HIGH YIELD AND INCOME ETF Ticker: IBHD                                 Stock Exchange: Cboe BZX

Investment Objective

The iShares iBonds 2024 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2024.

Fees and Expenses

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the "Trust") and BlackRock Fund Advisors ("BFA") (the "Investment Advisory Agreement") provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur "Acquired Fund Fees and Expenses." Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the "Prospectus").

You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:

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

Annual Fund Operating Expenses	Management Fees	Distribution and Service (12b-1) Fees	Other Expenses		Acquired Fund Fees and Expenses		Total Annual Fund Operating Expenses	Fee Waiver		Total Annual Fund Operating Expenses After Fee Waiver
iShares iBonds 2024 Term High Yield and Income ETF | iShares iBonds 2024 Term High Yield and Income ETF	0.35%	none	none	[1]	none	[1],[2]	0.35%	none	[1],[2]	0.35%

Example.

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:

Expense Example	1 Year	3 Years
iShares iBonds 2024 Term High Yield and Income ETF | iShares iBonds 2024 Term High Yield and Income ETF | USD ($)	36	113

Portfolio Turnover.

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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 10% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2024 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2024, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2023 and before December 16, 2024. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services industry or sector. The components of the Underlying Index are likely to change over time.

The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis.

The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest.

The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2024. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's^® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2024, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index.

The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index.

The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2024, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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.

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor.

Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund.

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

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.

Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests.

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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Credit Risk. Debt issuers and other counterparties may be unable or unwilling to make timely interest and/or principal payments when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s 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.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Declining Yield Risk. During the six 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.

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.

High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.”

Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV.

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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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.

Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition.

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

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

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results.

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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.

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.

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

Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund.

Reinvestment Risk. The Fund 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.

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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk.

Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

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.

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

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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES.

Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.

Performance Information

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

[1] The amount rounded to 0.00%.

[2] 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, 2024. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
iShares iBonds 2024 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® iBONDS® 2024 TERM HIGH YIELD AND INCOME ETF Ticker: IBHD                                 Stock Exchange: Cboe BZX
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares iBonds 2024 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2024.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the "Trust") and BlackRock Fund Advisors ("BFA") (the "Investment Advisory Agreement") provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur "Acquired Fund Fees and Expenses." Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the "Prospectus"). You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	December 15, 2024
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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 10% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	10.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2024 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2024, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2023 and before December 16, 2024. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the communication services industry or sector. The components of the Underlying Index are likely to change over time. The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis. The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest. The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2024. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2024, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index. The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2024, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor. Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. 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. Communication Services Sector Risk. Companies in the communications sector may be affected by industry competition, substantial capital requirements, government regulation, cyclicality of revenues and earnings, obsolescence of communications products and services due to technological advancement, a potential decrease in the discretionary income of targeted individuals and changing consumer tastes and interests. 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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Credit Risk. Debt issuers and other counterparties may be unable or unwilling to make timely interest and/or principal payments when due or otherwise honor their obligations. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s 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. Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests. Declining Yield Risk. During the six 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. 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. High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.” Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV. 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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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. Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts. Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results. 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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. 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. Passive Investment Risk. The Fund is not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Reinvestment Risk. The Fund 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. 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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk. Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. 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. Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders. 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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES. Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
iShares iBonds 2024 Term High Yield and Income ETF | iShares iBonds 2024 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.35%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none	[1]
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.35%
Fee Waiver	rr_FeeWaiverOrReimbursementOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses After Fee Waiver	rr_NetExpensesOverAssets	0.35%
1 Year	rr_ExpenseExampleYear01	$ 36
3 Years	rr_ExpenseExampleYear03	$ 113

[1] The amount rounded to 0.00%.

[2] 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, 2024. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

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iShares iBonds 2025 Term High Yield and Income ETF

iSHARES® iBONDS® 2025 TERM HIGH YIELD AND INCOME ETF Ticker: IBHE                                 Stock Exchange: Cboe BZX

Investment Objective

The iShares iBonds 2025 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2025.

Fees and Expenses

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the "Trust") and BlackRock Fund Advisors ("BFA") (the "Investment Advisory Agreement") provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur "Acquired Fund Fees and Expenses." Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the "Prospectus").

You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:

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

Annual Fund Operating Expenses	Management Fees	Distribution and Service (12b-1) Fees	Other Expenses		Acquired Fund Fees and Expenses		Total Annual Fund Operating Expenses	Fee Waiver		Total Annual Fund Operating Expenses After Fee Waiver
iShares iBonds 2025 Term High Yield and Income ETF | iShares iBonds 2025 Term High Yield and Income ETF	0.35%	none	none	[1]	none	[1],[2]	0.35%	none	[1],[2]	0.35%

Example.

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:

Expense Example	1 Year	3 Years
iShares iBonds 2025 Term High Yield and Income ETF | iShares iBonds 2025 Term High Yield and Income ETF | USD ($)	36	113

Portfolio Turnover.

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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 5% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2025 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2025, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2024 and before December 16, 2025. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the consumer cyclical and consumer staples industries or sectors. The components of the Underlying Index are likely to change over time.

The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis.

The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest.

The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2025. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's^® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2025, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index.

The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index.

The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2025, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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.

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor.

Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes.

Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund.

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.

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.

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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Consumer Cyclical Industry Risk. Consumer cyclical companies rely heavily on business cycles and economic conditions. Consumer cyclical companies may be adversely affected by domestic and international economic downturns, changes in exchange and interest rates, competition, consumers’ disposable income and preferences, social trends and marketing campaigns.

Consumer Staples Sector Risk. The consumer staples sector may be affected by, among other things, marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices.

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.

Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests.

Declining Yield Risk. During the six 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.

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.

High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.”

Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV.

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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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.

Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition.

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

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

Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results.

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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.

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.

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

Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund.

Reinvestment Risk. The Fund 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.

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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk.

Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

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.

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

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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES.

Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.

Performance Information

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

[1] The amount rounded to 0.00%.

[2] 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, 2025. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
iShares iBonds 2025 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® iBONDS® 2025 TERM HIGH YIELD AND INCOME ETF Ticker: IBHE                                 Stock Exchange: Cboe BZX
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares iBonds 2025 Term High Yield and Income ETF (the “Fund”) seeks to track the investment results of an index composed of U.S. dollar-denominated, high yield and other income generating corporate bonds maturing in 2025.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the "Trust") and BlackRock Fund Advisors ("BFA") (the "Investment Advisory Agreement") provides that BFA will pay all operating expenses of the Fund, except the management fees, interest expenses, taxes, expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, distribution fees or expenses, litigation expenses and any extraordinary expenses. The Fund may incur "Acquired Fund Fees and Expenses." Acquired Fund Fees and Expenses reflect the Fund's pro rata share of the fees and expenses incurred by investing in other investment companies. The impact of Acquired Fund Fees and Expenses is included in the total returns of the Fund. Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the "Prospectus"). You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	December 15, 2025
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. From inception (May 7, 2019) to the most recent fiscal year end, the Fund's portfolio turnover rate was 5% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	5.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions and other charges when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	Acquired Fund Fees and Expenses are not included in the calculation of the ratio of expenses to average net assets shown in the Financial Highlights section of the Fund's prospectus (the “Prospectus”).
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to meet its investment objective generally by investing in component securities of the Bloomberg Barclays 2025 Term High Yield and Income Index (the “Underlying Index”). The Fund may also invest in other exchange-traded funds (“ETFs”), 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, 2025, 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, fixed-rate, high yield and BBB or equivalently rated (as determined by Bloomberg Index Services Limited (the “Index Provider” or “Bloomberg”)) corporate bonds scheduled to mature after December 31, 2024 and before December 16, 2025. Securities eligible for inclusion in the Underlying Index are selected from a universe of corporate issuers (e.g., industrial, financial institutions, utilities) determined by Bloomberg. As of October 31, 2019, a significant portion of the Underlying Index is represented by securities of companies in the consumer cyclical and consumer staples industries or sectors. The components of the Underlying Index are likely to change over time. The bonds in the Underlying Index have $250 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”). Subject to the methodology of the Underlying Index discussed below, the securities in the Underlying Index may carry a coupon that steps-up according to a predetermined schedule (i.e., the interest rate paid on such securities will increase over time). The Underlying Index will be subject to issuer limits of 3%, with any excess redistributed among the remaining constituents on a pro-rata basis. The Underlying Index consists of bonds chosen from two sub-indices, the Bloomberg Barclays U.S. High Yield Index (the “High Yield Index”) and the Bloomberg Barclays U.S. Corporate Index (the “Corporate Index”), both of which are stripped of securities maturing outside of the maturity range defined above. BBB-rated bonds from the Corporate Index will be introduced to the Underlying Index under the following conditions: (1) in the last 2.5 years but before the last 6 months of the Underlying Index’s term, the Underlying Index will add BBB-rated bonds as constituent high yield bonds are called, no longer qualify for inclusion (due to, among other factors, sector reclassifications of issuers, changes in the credit rating of bonds included in the Underlying Index or rebalances to maintain issuer limits), or decline in value compared to a reference point set at 2.5 years from the Underlying Index’s term or (2) if, prior to the last 2.5 years remaining in the Underlying Index’s term, the market value of the high yield bonds in the Underlying Index declines below $30 billion, the Underlying Index will add BBB-rated bonds to maintain a $30 billion minimum market value for the Underlying Index. In the final year of the Underlying Index’s term, any principal and interest paid by index constituents is treated as follows: (1) during the first six months of the final year, the Underlying Index reinvests proceeds pro-rata into the remaining bonds in the Underlying Index, and (2) during the last six months of the final year, proceeds are not reinvested and are presumed to be held in cash while earning no interest. The securities in the Underlying Index are updated on the last calendar day of each month until six months until maturity with the last rebalance date on June 30, 2025. 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 “high yield” to be selected from the High Yield Index and “BBB” to be selected from the Corporate Index. The bonds from the High Yield Index must have a rating equal to or below “Ba1”/”BB+”/”BB+” and above “CC”. The bonds from the Corporate Index must have a rating of “BBB” (or equivalent). The Index Provider will use the middle rating of Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor's® Global Ratings, a subsidiary of S&P Global (“S&P Global Ratings”) and Fitch Ratings, Inc. (“Fitch”); when a rating from only two agencies is available, the lower is used; when only one agency rates a bond, that rating is used. As the Fund approaches its termination date, its holdings of money market or similar funds may increase, causing the Fund to incur the fees and expenses of these funds. By December 15, 2025, the Underlying Index value will be represented almost entirely by cash as no securities will remain in the Underlying Index. The Fund is a series of the iShares iBonds fixed maturity series of bond ETFs sponsored by BlackRock, Inc. (“BlackRock”). The iShares iBonds fixed maturity series do not invest in U.S. savings bonds or other U.S. government bonds (except to the extent the funds hold cash equivalent instruments consistent with their investment objectives) and are not designed to provide protection against inflation. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by aiming to keep portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of an applicable underlying index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market value and industry weightings), fundamental characteristics (such as return variability, duration, maturity, 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 generally will invest at least 90% of its assets in the component securities of the Underlying Index, except during the last months of the Fund’s operations, as described below, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates (“BlackRock Cash Funds”), as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. From time to time when conditions warrant, however, the Fund may invest at least 80% of its assets in the component securities of the Underlying Index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents, including shares of BlackRock Cash Funds, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. In the last six months of operation, as the bonds held by the Fund mature, the proceeds will not be reinvested by the Fund in bonds but instead will be held in cash and cash equivalents. By December 15, 2025, the Underlying Index is expected to consist almost entirely of cash acquired in this manner. On or around this date, the Fund will wind up and terminate, and its net assets will be distributed to then-current shareholders pursuant to a plan of liquidation. The Fund should not be confused with a target date fund, which has assets that are managed according to a particular investment strategy that convert 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
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value per share (“NAV”), trading price, yield, total return and ability to meet its investment objective. The order of the below risk factors does not indicate the significance of any particular risk factor. Asset Class Risk. Securities and other assets in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general financial markets, a particular financial market or other asset classes. Assets Under Management (AUM) Risk. From time to time, an Authorized Participant (as defined in the Creations and Redemptions section of the Prospectus, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or a fund may invest in the Fund and hold its investment for a specific period of time to allow the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units (as defined in the Purchase and Sale of Fund Shares section of the Prospectus), Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting. 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. 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 and/or other assets of a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Consumer Cyclical Industry Risk. Consumer cyclical companies rely heavily on business cycles and economic conditions. Consumer cyclical companies may be adversely affected by domestic and international economic downturns, changes in exchange and interest rates, competition, consumers’ disposable income and preferences, social trends and marketing campaigns. Consumer Staples Sector Risk. The consumer staples sector may be affected by, among other things, marketing campaigns, changes in consumer demands, government regulations and changes in commodity prices. 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. Cybersecurity Risk. Failures or breaches of the electronic systems of the Fund, the Fund's adviser, distributor, the Index Provider and other service providers, market makers, Authorized Participants or the issuers of securities in which the Fund invests have the ability to cause disruptions, negatively impact the Fund’s business operations and/or potentially result in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cybersecurity plans and systems of the Fund’s Index Provider and other service providers, market makers, Authorized Participants or issuers of securities in which the Fund invests. Declining Yield Risk. During the six 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. 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. High Yield Securities Risk. Securities that are rated below investment-grade (commonly referred to as “junk bonds,” which may include those bonds rated below “BBB-” by S&P Global Ratings and Fitch, or “Baa3” by Moody's), or are unrated, may be deemed speculative, may involve greater levels of risk than higher-rated securities of similar maturity and may be more likely to default. BBB-rated bonds, although investment-grade, may share some of the same speculative characteristics as “junk bonds.” Illiquid Investments Risk. The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. 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 the returns of the Fund because the Fund may be unable to transact at advantageous times or prices. During periods of market volatility, liquidity in the market for the Fund’s shares may be impacted by the liquidity in the market for the underlying securities or instruments held by the Fund, which could lead to the Fund’s shares trading at a premium or discount to the Fund’s NAV. 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 instruments 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 or when the BBB-rated bonds are added to the Underlying Index as constituent high yield bonds are called, no longer qualify for inclusion or decline in value compared to a reference point. Such change may result in a net decrease in the average yield of bonds held by the Fund. 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. Index-Related Risk. There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the Index Provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. To the extent that the Underlying Index includes a non-standard methodology, errors in index data, index computation or the construction of the Underlying Index may be more likely to occur. Unusual market conditions may cause the Index Provider to postpone a scheduled rebalance, which could cause the Underlying Index to vary from its normal or expected composition. Infectious Illness Risk. An outbreak of an infectious respiratory illness, COVID-19, caused by a novel coronavirus has resulted in travel restrictions, disruption of healthcare systems, prolonged quarantines, cancellations, supply chain disruptions, lower consumer demand, layoffs, ratings downgrades, defaults and other significant economic impacts. Certain markets have experienced temporary closures, extreme volatility, severe losses, reduced liquidity and increased trading costs. These events will have an impact on the Fund and its investments and could impact the Fund’s ability to purchase or sell securities or cause elevated tracking error and increased premiums or discounts to the Fund’s NAV. Other infectious illness outbreaks in the future may result in similar impacts. Interest Rate Risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates. Additionally, under certain market conditions in which interest rates are low and the market prices for portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. An increase in interest rates will generally cause the value of securities held by the Fund to decline, may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments, including those held by the Fund. The historically low interest rate environment heightens the risks associated with rising interest rates. Issuer Risk. The performance of the Fund depends on the performance of individual securities to which the Fund has exposure. The Fund may be adversely affected if an issuer of underlying securities held by the Fund is unable or unwilling to repay principal or interest when due. Changes to the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Management Risk. As the Fund will not fully replicate the Underlying Index, it is subject to the risk that BFA's investment strategy may not produce the intended results. 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, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the Fund’s NAV. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. 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. Passive Investment Risk. The Fund is not actively managed, and BFA generally does not attempt to take defensive positions under any market conditions, including declining markets. Privately Issued Securities Risk. The Fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the 1933 Act. Privately issued securities are securities that have not been registered under the 1933 Act and as a result may be subject to legal restrictions on resale. Privately issued securities are generally not traded on established markets. As a result of the absence of a public trading market, privately issued securities may be deemed to be illiquid investments, may be more difficult to value than publicly traded securities and may be subject to wide fluctuations in value. Delay or difficulty in selling such securities may result in a loss to the Fund. Reinvestment Risk. The Fund 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. 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. Through its holdings of securities of certain issuers, the Fund is specifically exposed to Asian Economic Risk and North American Economic Risk. Risk of Investing in the U.S. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. 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. Small Fund Risk. When the Fund’s size is small, the Fund may experience low trading volume and wide bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause the Fund to incur elevated transaction costs for the Fund and negative tax consequences for its shareholders. 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 because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund's valuation of a security at the time of calculation of the Fund's NAV), transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of distributions, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index or the costs to the Fund of complying with various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not. INDEX ETFs THAT TRACK INDICES WITH SIGNIFICANT WEIGHT IN HIGH YIELD SECURITIES MAY EXPERIENCE HIGHER TRACKING ERROR THAN OTHER INDEX ETFs THAT DO NOT TRACK SUCH INDICES. Valuation Risk. Because the bond market may be open on days or during time periods when the Fund does not price its shares, the value of the securities or other assets in the Fund’s portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund’s shares.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	As of the date of the Prospectus, the Fund has been in operation for less than one full calendar year and therefore does not report its performance information.
iShares iBonds 2025 Term High Yield and Income ETF | iShares iBonds 2025 Term High Yield and Income ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.35%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none	[1]
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.35%
Fee Waiver	rr_FeeWaiverOrReimbursementOverAssets	none	[1],[2]
Total Annual Fund Operating Expenses After Fee Waiver	rr_NetExpensesOverAssets	0.35%
1 Year	rr_ExpenseExampleYear01	$ 36
3 Years	rr_ExpenseExampleYear03	$ 113

[1] The amount rounded to 0.00%.

[2] 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, 2025. The contractual waiver may be terminated prior to the Fund's termination only upon the written agreement of the Trust and BFA.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Feb. 28, 2020
Document Creation Date	dei_DocumentCreationDate	Jun. 30, 2020