S000069740 [Member] Investment Strategy - iShares US Small Cap Value Factor ETF	Mar. 31, 2026
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	The Fund seeks to track the investment results of the Russell 2000 Focused Value Select Index (the “Underlying Index”), which is an equal-weighted equity index provided by FTSE Russell (the “Index Provider” or “Russell”). The Underlying Index measures the performance of small-capitalization U.S. companies with prominent value factor characteristics, as determined by the Index Provider. The Underlying Index is a subset of the Russell 2000® Index (the “Parent Index”), which measures the performance of the small-capitalization segment of the U.S. equity market, as defined by the Index Provider. The construction of the Underlying Index begins with the Parent Index and excludes companies that are ranked in the least liquid 20% (i.e. approximately 391 constituents) based on the 60-day average dollar value traded. The list of eligible constituents is then narrowed to exclude the top 20% of Parent Index constituents with the highest risk based on a 12-month trailing realized volatility. The list is further narrowed to exclude the top 20% of Parent Index constituents with the highest leverage, which is measured by comparing a company’s total debt to its total assets. Following these three initial screens, the remaining companies are evaluated to exclude companies with a negative sentiment score, which is calculated using the number of upgrades for earnings per share and the number of downgrades for earnings per share for a company's current and next fiscal year. A company with more downgrades for earnings per share than upgrades will have a negative sentiment score. The remaining companies are then ranked based on a weighted composite score of three value factor metrics: price-to-book, price-to-earnings and price-to-cash flow from operations (the “Composite Score”). The top 250 ranked stocks are selected and equally weighted to form a baseline or target composition (the “Target Index”). Industry exposure is capped so that the difference between an industry weight in the Target Index and in the Parent Index is less than 5%. The Underlying Index is reviewed monthly and will be rebalanced to the Target Index if there is a greater than 10% difference between an industry weight in the Underlying Index and in the Parent Index. It will also be rebalanced if either of the following conditions are met: (i) the Underlying Index’s Composite Score is less than 90% of the Target Index's Composite Score; or (ii) the Underlying Index has fewer than 200 securities. If no rebalance is triggered, the component securities of the Underlying Index and their weights will remain unchanged. The Underlying Index may contain fewer than 250 stocks and may not rebalance for a period of time. As of March 31, 2026, a significant portion of the Underlying Index was represented by securities of companies in the consumer goods and services, financials and industrials industries or sectors. The components of the Underlying Index are likely to change over time. As of March 31, 2026, the Underlying Index had 238 components. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. 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 or other instruments intended to collectively have an investment profile similar to that of an applicable underlying index. The instruments selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the components of the Underlying Index. The Fund may use derivatives to gain or reduce exposure to the components of the Underlying Index or exposure to one or more market risk factors associated with such components. Subject to the limits described herein, the Fund may purchase and hold cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates, and may also purchase and hold instruments not included in the Underlying Index when BFA believes that such instruments will help the Fund track the performance of the Underlying Index over time, including in light of expected liquidity or trading costs, anticipated additions to or deletions from the Underlying Index, or other reasons as determined by BFA. In accordance with Rule 35d-1 under the Investment Company Act of 1940, as amended (the “1940 Act”), under normal circumstances, the Fund will not invest less than 80% of the value of its net assets, plus the amount of any borrowings for investment purposes, in components of its Underlying Index. Investments in derivatives and other investments will be counted toward the Fund’s 80% investment policy to the extent that they provide exposure to the components of its Underlying Index or exposure to one or more market risk factors associated with such components. The Fund’s 80% investment policy may be changed by the Trust’s Board of Trustees (the “Board”) upon 60 days’ notice to shareholders. 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 Russell, which is part of the London Stock Exchange Group and is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the components of the Underlying Index and publishes information regarding the market value of the Underlying Index. Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.
Strategy Portfolio Concentration [Text]	Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.

The Fund seeks to track the investment results of the Russell 2000 Focused Value Select Index (the “Underlying Index”), which is an equal-weighted equity index provided by FTSE Russell (the “Index Provider” or “Russell”). The Underlying Index measures the performance of small-capitalization U.S. companies with prominent value factor characteristics, as determined by the Index Provider. The Underlying Index is a subset of the Russell 2000® Index (the “Parent Index”), which measures the performance of the small-capitalization segment of the U.S. equity market, as defined by the Index Provider.

The construction of the Underlying Index begins with the Parent Index and excludes companies that are ranked in the least liquid 20% (i.e. approximately 391 constituents) based on the 60-day average dollar value traded. The list of eligible constituents is then narrowed to exclude the top 20% of Parent Index constituents with the highest risk based on a 12-month trailing realized volatility. The list is further narrowed to exclude the top 20% of Parent Index constituents with the highest leverage, which is measured by comparing a company’s total debt to its total assets.

Following these three initial screens, the remaining companies are evaluated to exclude companies with a negative sentiment score, which is calculated using the number of upgrades for earnings per share and the number of downgrades for earnings per share for a company's current and next fiscal year. A company with more downgrades for earnings per share than upgrades will have a negative sentiment score.

The remaining companies are then ranked based on a weighted composite score of three value factor metrics: price-to-book, price-to-earnings and price-to-cash flow from operations (the “Composite Score”). The top 250 ranked stocks are selected and equally weighted to form a baseline or target composition (the “Target Index”).

Industry exposure is capped so that the difference between an industry weight in the Target Index and in the Parent Index is less than 5%. The Underlying Index is reviewed monthly and will be rebalanced to the Target Index if there is a greater than 10% difference between an industry weight in the Underlying Index and in the Parent Index. It will also be rebalanced if either of the following conditions are met: (i) the Underlying Index’s Composite Score is less than 90% of the Target Index's Composite Score; or (ii) the Underlying Index has fewer than 200 securities. If no rebalance is triggered, the component securities of the Underlying Index and their weights will remain unchanged. The Underlying Index may contain fewer than 250 stocks and may not rebalance for a period of time.

As of March 31, 2026, a significant portion of the Underlying Index was represented by securities of companies in the consumer goods and services, financials and industrials industries or sectors. The components of the Underlying Index are likely to change over time. As of March 31, 2026, the Underlying Index had 238 components.

The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. 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 or other instruments intended to collectively have an investment profile similar to that of an applicable underlying index. The instruments selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of an applicable underlying index. The Fund may or may not hold all of the components of the Underlying Index. The Fund may use derivatives to gain or reduce exposure to the components of the Underlying Index or exposure to one or more market risk factors associated with such components. Subject to the limits described herein, the Fund may purchase and hold cash and cash equivalents, including shares of money market funds advised by BFA or its affiliates, and may also purchase and hold instruments not included in the Underlying Index when BFA believes that such instruments will help the Fund track the performance of the Underlying Index over time, including in light of expected liquidity or trading costs, anticipated additions to or deletions from the Underlying Index, or other reasons as determined by BFA.

In accordance with Rule 35d-1 under the Investment Company Act of 1940, as amended (the “1940 Act”), under normal circumstances, the Fund will not invest less than 80% of the value of its net assets, plus the amount of any borrowings for investment purposes, in components of its Underlying Index. Investments in derivatives and other investments will be counted toward the Fund’s 80% investment policy to the extent that they provide exposure to the components of its Underlying Index or exposure to one or more market risk factors associated with such components. The Fund’s 80% investment policy may be changed by the Trust’s Board of Trustees (the “Board”) upon 60 days’ notice to shareholders.

The Underlying Index is sponsored by Russell, which is part of the London Stock Exchange Group and is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the components of the Underlying Index and publishes information regarding the market value of the Underlying Index.

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.