v3.26.3
Investor A C And Institutional [Member] Expense Example - Investor A C and Institutional - BlackRock California Municipal Opportunities Fund
May 31, 2026
USD ($)
Institutional  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 46
Expense Example, with Redemption, 3 Years 162
Expense Example, with Redemption, 5 Years 288
Expense Example, with Redemption, 10 Years 657
Investor A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 493
Expense Example, with Redemption, 3 Years 650
Expense Example, with Redemption, 5 Years 819
Expense Example, with Redemption, 10 Years 1,311
Investor C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 248
Expense Example, with Redemption, 3 Years 471
Expense Example, with Redemption, 5 Years 818
Expense Example, with Redemption, 10 Years $ 1,591