Investment Strategy - iShares Developed Real Estate Index Fund	Jan. 31, 2026
Investor A Institutional [Member]
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	The Fund seeks to track the investment results of the FTSE EPRA Nareit Developed Index (the “Underlying Index”), which measures the stock performance of companies engaged in the ownership, disposal and development of income-producing real estate in developed countries as defined by FTSE EPRA Nareit. As of April 30, 2026, the Underlying Index was comprised of stocks of companies in the following markets: Australia, Austria, Belgium, Canada, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Norway, Singapore, Spain, Sweden, Switzerland, the United Kingdom and the United States. The Underlying Index may include large-, mid- or small-capitalization companies, and components primarily include real estate investment trusts (“REITs”). The components of the Underlying Index, and the degree to which these components represent certain industries, may change over time. BlackRock 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 the Underlying Index. The securities 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 the Underlying Index. The Fund may or may not hold all of the securities in the Underlying Index. The Fund generally invests at least 90% of its assets, plus the amount of any borrowing for investment purposes, in securities of the Underlying Index and in depositary receipts representing securities of the Underlying Index. 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.
Strategy Portfolio Concentration [Text]	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.
Class K
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	The Fund seeks to track the investment results of the FTSE EPRA Nareit Developed Index (the “Underlying Index”), which measures the stock performance of companies engaged in the ownership, disposal and development of income-producing real estate in developed countries as defined by FTSE EPRA Nareit. As of April 30, 2026, the Underlying Index was comprised of stocks of companies in the following markets: Australia, Austria, Belgium, Canada, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Norway, Singapore, Spain, Sweden, Switzerland, the United Kingdom and the United States. The Underlying Index may include large-, mid- or small-capitalization companies, and components primarily include real estate investment trusts (“REITs”). The components of the Underlying Index, and the degree to which these components represent certain industries, may change over time. BlackRock 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 the Underlying Index. The securities 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 the Underlying Index. The Fund may or may not hold all of the securities in the Underlying Index. The Fund generally invests at least 90% of its assets, plus the amount of any borrowing for investment purposes, in securities of the Underlying Index and in depositary receipts representing securities of the Underlying Index. 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.
Strategy Portfolio Concentration [Text]	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.