Shareholder Report, Line Graph (Details) 1014021_Franklin Municipal Green Bond ETF_Single Class_TSR Annual {Single Class} - USD ($) |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
Mar. 31, 2022 |
Mar. 31, 2021 |
Mar. 31, 2020 |
Mar. 31, 2019 |
Mar. 31, 2018 |
Aug. 31, 2017 |
Mar. 31, 2026 |
|
| Franklin Municipal Green Bond ETF | ||||||||||
| Account Value [Line Items] | ||||||||||
| Line Graph and Table Measure Name | Franklin Municipal Green Bond ETF (NAV) | |||||||||
| Accumulated Value | $ 11,488 | $ 11,324 | $ 10,856 | $ 11,042 | $ 11,677 | $ 11,104 | $ 10,483 | $ 9,855 | $ 10,000 | $ 12,019 |
| Bloomberg Municipal Bond Index [Member] | ||||||||||
| Account Value [Line Items] | ||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | |||||||||
| Accumulated Value | $ 11,443 | $ 11,305 | $ 10,963 | $ 10,934 | $ 11,446 | $ 10,848 | $ 10,446 | $ 9,913 | $ 10,000 | $ 11,934 |