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Shareholder Report, Average Annual Return (Details) LMF5100_Western Asset Municipal High Income Fund_Class C_TSR Annual {Class C}
12 Months Ended 60 Months Ended 120 Months Ended
Jul. 31, 2026
Jul. 31, 2026
Jul. 31, 2026
Class C      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class C (with sales charge)    
Average Annual Return, Percent 5.63% 0.19% 1.67%
Without Sales Load [Member] | Class C      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class C    
Average Annual Return, Percent 6.63% 0.19% 1.67%
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%