v3.26.1
Shareholder Report, Average Annual Return (Details) LMF5600_Western Asset Oregon Municipals Fund_Class I_TSR Annual {Class I}
12 Months Ended 60 Months Ended 120 Months Ended
Apr. 30, 2026
Apr. 30, 2026
Apr. 30, 2026
Class I      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class I    
Average Annual Return, Percent 5.97% 0.69% 1.76%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 6.34% 0.90% 2.20%
Bloomberg Oregon Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Oregon Municipal Bond Index    
Average Annual Return, Percent 6.70% 0.62% 2.04%