v3.26.1
Shareholder Report, Line Graph (Details) 1014018_Franklin U.S. Mid Cap Multifactor Index 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
Apr. 26, 2017
Mar. 31, 2026
Franklin U.S. Mid Cap Multifactor Index ETF                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   Franklin U.S. Mid Cap Multifactor Index ETF (NAV)
Accumulated Value $ 23,072 $ 22,978 $ 18,376 $ 18,784 $ 16,894 $ 10,196 $ 12,211 $ 11,009 $ 10,000 $ 24,300
Russell 3000 Index [Member]                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   Russell 3000 Index
Accumulated Value 25,662 23,934 18,512 20,249 18,092 11,131 12,249 11,262 10,000 $ 30,303
Russell Midcap Index [Member]                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   Russell Midcap Index
Accumulated Value 20,586 20,065 16,400 17,979 16,816 9,684 11,854 11,134 10,000 $ 23,875
LibertyQ U.S. Mid Cap Equity Index [Member]                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   LibertyQ U.S. Mid Cap Equity Index
Accumulated Value $ 23,716 $ 23,554 $ 18,777 $ 19,148 $ 17,176 $ 10,334 $ 12,348 $ 11,099 $ 10,000 $ 25,055