v3.26.1
S000003870 [Member] Annual Fund Operating Expenses - BlackRock Government Money Market Portfolio
Dec. 31, 2025
Prospectus [Line Items]  
Fee Waiver or Reimbursement over Assets, Date of Termination June 30, 2027
BlackRock Government Money Market Portfolio  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.37%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.24%
Expenses (as a percentage of Assets) 0.61%
Fee Waiver or Reimbursement (0.18%) [1]
Net Expenses (as a percentage of Assets) 0.43% [1]
[1] As described in the “Management of the Funds” section of the Fund’s prospectus, BlackRock Advisors, LLC (“BlackRock”) has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.43% of average daily net assets through June 30, 2027. BlackRock has also contractually agreed to reimburse fees in order to limit certain networking and operational/recordkeeping fees to 0.02% of average daily net assets through June 30, 2027. Each of these contractual agreements may be terminated upon 90 days’ notice by a majority of the non‑interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.