S000046220 [Member] Average Annual Total Returns

12 Months Ended

60 Months Ended

120 Months Ended

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

Bloomberg Municipal Bond Index (Reflects no deduction for fees, expenses or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

4.25%

0.80%

2.34%

Bloomberg Municipal High Yield Bond Index

Prospectus [Line Items]

Average Annual Return, Percent

2.46%

2.18%

4.35%

Customized Reference Benchmark

Prospectus [Line Items]

Average Annual Return, Percent

3.15%

1.78%

^[1]

BATS: High Income Municipal Series

Prospectus [Line Items]

Average Annual Return, Percent

3.19%

2.21%

4.28%

BATS: High Income Municipal Series | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

3.19%

2.08%

4.15%

BATS: High Income Municipal Series | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

3.94%

2.67%

4.28%

[1]	The Customized Reference Benchmark commenced in September 2016 and therefore the Customized Reference Benchmark does not have a return for the 10 years ended December 31, 2025.