v3.26.3
Investor A1 [Member] Shareholder Fees - Investor A1 [Member] - BlackRock Strategic Municipal Opportunities Fund of BlackRock Municipal Series Trust - Investor A1 Shares
May 31, 2026
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00% [1]
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00% [2]
[1] Investor A1 Shares are subject to a maximum sales charge on purchases of 1.00%. The sales charge does not apply to dividend and capital gain reinvestments by existing shareholders and new purchases for certain employer-sponsored retirement plans, which are currently the only investors who may invest in Investor A1 Shares.
[2] A contingent deferred sales charge (“CDSC”) of 1.00% is assessed on certain redemptions of Investor A1 Shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase. The CDSC does not apply to redemptions by certain employer-sponsored retirement plans or to redemptions of shares acquired through reinvestment of dividends and capital gains by existing shareholders.