v3.25.2
Investor A1 [Member] N-1A Cover
May 31, 2025
Prospectus [Line Items]  
Document Type 485BPOS
Amendment Flag false
Registrant Name BlackRock Municipal Series Trust
Entity Central Index Key 0000799113
Entity Investment Company Type N-1A
Document Period End Date May 31, 2025
Prospectus Date Sep. 26, 2025