v3.26.3
Shareholder Report, Average Annual Return (Details) LMF5100_Western Asset Municipal High Income Fund_Class A_TSR Annual {Class A}
12 Months Ended 60 Months Ended 120 Months Ended
Jul. 31, 2026
Jul. 31, 2026
Jul. 31, 2026
Class A      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A (with sales charge)    
Average Annual Return, Percent 3.07% (0.15%) 1.80%
Without Sales Load [Member] | Class A      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A    
Average Annual Return, Percent 7.09% 0.72% 2.24%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 5.27% 0.51% 1.95%