v3.25.2
S000027380 [Member] Expense Example - AB High Income Municipal Portfolio
May 31, 2025
USD ($)
Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 411
Expense Example, with Redemption, 3 Years 645
Expense Example, with Redemption, 5 Years 898
Expense Example, with Redemption, 10 Years 1,622
Class C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 290 [1]
Expense Example, with Redemption, 3 Years 588
Expense Example, with Redemption, 5 Years 1,011
Expense Example, with Redemption, 10 Years 1,995
Advisor Class  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 89
Expense Example, with Redemption, 3 Years 278
Expense Example, with Redemption, 5 Years 482
Expense Example, with Redemption, 10 Years 1,073
Class Z  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 89
Expense Example, with Redemption, 3 Years 278
Expense Example, with Redemption, 5 Years 482
Expense Example, with Redemption, 10 Years $ 1,073
[1]
If you did not redeem your shares at the end of the period, your expenses would be decreased by approximately $100.