Expense Example - Investor A, Institutional - BlackRock U.S. Impact Fund	Feb. 09, 2021 USD ($)
Institutional Shares
Expense Example:
Expense Example, with Redemption, 1 Year	$ 87
Expense Example, with Redemption, 3 Years	271
Investor A Shares
Expense Example:
Expense Example, with Redemption, 1 Year	631
Expense Example, with Redemption, 3 Years	$ 856

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection example
-Paragraph 1
-Subparagraph 2

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Period Type:	duration