v3.26.1
Shareholder Report, Average Annual Return (Details) 1014020_Franklin Dynamic Municipal Bond ETF_Single Class_TSR Annual {Single Class}
12 Months Ended 60 Months Ended 103 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Franklin Dynamic Municipal Bond ETF      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Franklin Dynamic Municipal Bond ETF (NAV)    
Average Annual Return, Percent 5.63% 2.21% 2.88%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 4.29% 0.84% 2.08%
Bloomberg Municipal 1-15 Year Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal 1-15 Year Index    
Average Annual Return, Percent 4.49% 1.17% 2.07%