v3.26.3
Investor A C and Institutional [Member] Expense Example, No Redemption - Investor A C and Institutional - BlackRock Strategic Municipal Opportunities Fund of BlackRock Municipal Series Trust - Investor C Shares
May 31, 2026
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 194
Expense Example, No Redemption, 3 Years 610
Expense Example, No Redemption, 5 Years 1,053
Expense Example, No Redemption, 10 Years $ 2,079