S000046220 [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
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 |
|
| BATS: High Income Municipal Series | BATS: High Income Municipal Series | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 3.19% | 5.54% | 8.11% | (13.29%) | 9.28% | 6.13% | 11.06% | 2.07% | 10.21% | 2.77% |