v3.26.1
Shareholder Report, Line Graph (Details) 1014017_Franklin U.S. Small 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. Small Cap Multifactor Index ETF                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   Franklin U.S. Small Cap Multifactor Index ETF (NAV)
Accumulated Value $ 17,265 $ 17,532 $ 14,539 $ 15,178 $ 15,175 $ 8,396 $ 11,170 $ 10,634 $ 10,000 $ 19,015
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 2000 Index [Member]                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   Russell 2000 Index
Accumulated Value 15,994 16,662 13,919 15,746 16,713 8,578 11,285 11,058 10,000 $ 20,109
LibertyQ U.S. Small Cap Equity Index [Member]                    
Account Value [Line Items]                    
Line Graph and Table Measure Name                   LibertyQ U.S. Small Cap Equity Index
Accumulated Value $ 17,898 $ 18,110 $ 14,961 $ 15,579 $ 15,533 $ 8,561 $ 11,361 $ 10,788 $ 10,000 $ 19,781