v3.26.1
Shareholder Report, Line Graph (Details) 1014041_Franklin Senior Loan 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
May 30, 2018
Mar. 31, 2026
Franklin Senior Loan ETF                  
Account Value [Line Items]                  
Line Graph and Table Measure Name                 Franklin Senior Loan ETF (NAV)
Accumulated Value $ 13,752 $ 12,972 $ 11,603 $ 11,317 $ 11,013 $ 9,842 $ 10,244 $ 10,000 $ 14,157
Bloomberg U.S. Aggregate Index [Member]                  
Account Value [Line Items]                  
Line Graph and Table Measure Name                 Bloomberg U.S. Aggregate Index
Accumulated Value 11,162 10,642 10,465 10,990 11,466 11,386 10,452 10,000 $ 11,647
Morningstar LSTA U.S. Leveraged Loan 100 Index [Member]                  
Account Value [Line Items]                  
Line Graph and Table Measure Name                 Morningstar LSTA U.S. Leveraged Loan 100 Index
Accumulated Value $ 14,141 $ 13,208 $ 11,776 $ 11,478 $ 11,220 $ 9,733 $ 10,261 $ 10,000 $ 14,980