Cash Reserve [Member] Expense Example - Cash Reserve - BLACKROCK LIQUID FEDERAL TRUST FUND - Cash Reserve Shares	Apr. 30, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 58
Expense Example, with Redemption, 3 Years	193
Expense Example, with Redemption, 5 Years	341
Expense Example, with Redemption, 10 Years	$ 769

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