Investment Strategy - BlackRock Summit Cash Reserves Fund	Apr. 30, 2025
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	The Fund invests at least 99.5% of its total assets in cash, U.S. Treasury bills, notes and other obligations issued or guaranteed as to principal and interest by the U.S. Government, its agencies or instrumentalities, and repurchase agreements secured by such obligations or cash. The Fund invests in securities maturing in 397 days (13 months) or less (with certain exceptions), and the portfolio will have a dollar-weighted average maturity of 60 days or less and a dollar-weighted average life of 120 days or less. The Fund may invest in variable and floating rate instruments, and transact in securities on a when-issued, delayed delivery or forward commitment basis. The securities purchased by the Fund are subject to the quality, diversification, and other requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “Investment Company Act”), and other rules of the Securities and Exchange Commission.

Investment Strategy - BlackRock Summit Cash Reserves Fund

Apr. 30, 2025

Principal Investment Strategies of the Fund

The Fund invests at least 99.5% of its total assets in cash, U.S. Treasury bills, notes and other obligations issued or guaranteed as to principal and interest by the U.S. Government, its agencies or instrumentalities, and repurchase agreements secured by such obligations or cash. The Fund invests in securities maturing in 397 days (13 months) or less (with certain exceptions), and the portfolio will have a dollar-weighted average maturity of 60 days or less and a dollar-weighted average life of 120 days or less. The Fund may invest in variable and floating rate instruments, and transact in securities on a when-issued, delayed delivery or forward commitment basis.

The securities purchased by the Fund are subject to the quality, diversification, and other requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “Investment Company Act”), and other rules of the Securities and Exchange Commission.