Administration [Member] Expense Example - Administration - BLACKROCK LIQUID FEDERAL TRUST FUND - ADMINISTRATION	Apr. 30, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 28
Expense Example, with Redemption, 3 Years	98
Expense Example, with Redemption, 5 Years	175
Expense Example, with Redemption, 10 Years	$ 401

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