v3.26.3
Shareholder Report, Average Annual Return (Details) LMF5900_Western Asset Short Duration 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 3.11% 4.04% 5.03%
Without Sales Load [Member] | Class A      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A    
Average Annual Return, Percent 5.46% 4.50% 5.27%
Bloomberg U.S. Aggregate Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. Aggregate Index    
Average Annual Return, Percent 2.71% (0.40%) 1.35%
Bloomberg US High Yield 1-5 Year Cash Pay 2% Constrained Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. High Yield 1-5 Year Cash Pay 2% Constrained Index    
Average Annual Return, Percent 4.96% 5.02% 5.56%