v3.26.3
Investor A C And Institutional [Member] Expense Example, No Redemption - Investor A C and Institutional - BlackRock California Municipal Opportunities Fund - Investor C
May 31, 2026
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 148
Expense Example, No Redemption, 3 Years 471
Expense Example, No Redemption, 5 Years 818
Expense Example, No Redemption, 10 Years $ 1,591