v3.26.1
Shareholder Report, Line Graph (Details) 1014015_Franklin Investment Grade Corporate 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
Mar. 31, 2017
Oct. 03, 2016
Mar. 31, 2026
Franklin Investment Grade Corporate ETF                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Franklin Investment Grade Corporate ETF (NAV)
Accumulated Value $ 11,681 $ 11,140 $ 10,698 $ 11,437 $ 11,951 $ 10,921 $ 10,498 $ 10,051 $ 9,817 $ 10,000 $ 12,210
Bloomberg U.S. Aggregate Index [Member]                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Bloomberg U.S. Aggregate Index
Accumulated Value 11,130 10,613 10,435 10,960 11,434 11,354 10,423 9,976 9,857 10,000 $ 11,614
Bloomberg U.S. Corporate - Investment Grade Index [Member]                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Bloomberg U.S. Corporate - Investment Grade Index
Accumulated Value $ 12,091 $ 11,526 $ 11,038 $ 11,686 $ 12,198 $ 11,219 $ 10,687 $ 10,184 $ 9,917 $ 10,000 $ 12,669