Shareholder Report, Line Graph (Details) 74200006200_Franklin Federal Intermediate-Term Tax-Free Income Fund_Class A1_TSR Annual {Class A1} - USD ($) |
12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Feb. 28, 2025 |
Feb. 29, 2024 |
Feb. 28, 2023 |
Feb. 28, 2022 |
Feb. 28, 2021 |
Feb. 29, 2020 |
Feb. 28, 2019 |
Feb. 28, 2018 |
Feb. 28, 2017 |
Feb. 29, 2016 |
Feb. 28, 2026 |
|
| Class A1 | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class A1 (with sales charge) | ||||||||||
| Accumulated Value | $ 11,133 | $ 10,727 | $ 10,195 | $ 10,682 | $ 10,820 | $ 10,726 | $ 10,103 | $ 9,817 | $ 9,706 | $ 9,775 | $ 11,749 |
| Bloomberg Municipal Bond Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||
| Accumulated Value | 12,112 | 11,764 | 11,159 | 11,759 | 11,837 | 11,713 | 10,700 | 10,276 | 10,025 | 10,000 | $ 12,713 |
| Bloomberg Municipal -5 Year Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal 1-15 Year Index | ||||||||||
| Accumulated Value | $ 11,937 | $ 11,605 | $ 11,093 | $ 11,434 | $ 11,564 | $ 11,407 | $ 10,596 | $ 10,178 | $ 10,002 | $ 10,000 | $ 12,607 |