S000027380 [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| AB High Income Municipal Portfolio | Class A | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 4.35% | 6.33% | (15.37%) | 6.23% | 4.92% | 10.54% | 0.84% | 9.91% | (0.15%) | 5.31% |