v3.26.1
Class A C F I I And Class I S [Member] Expense Example, No Redemption - Class A, C, FI, I and Class IS - Western Asset Short Duration Municipal Income Fund
Feb. 28, 2026
USD ($)
Class A  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 280
Expense Example, No Redemption, 3 Years 413
Expense Example, No Redemption, 5 Years 557
Expense Example, No Redemption, 10 Years 976
Class C  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 98
Expense Example, No Redemption, 3 Years 306
Expense Example, No Redemption, 5 Years 531
Expense Example, No Redemption, 10 Years 1,081
Class I  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 41
Expense Example, No Redemption, 3 Years 144
Expense Example, No Redemption, 5 Years 256
Expense Example, No Redemption, 10 Years 586
Class FI  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 77
Expense Example, No Redemption, 3 Years 259
Expense Example, No Redemption, 5 Years 457
Expense Example, No Redemption, 10 Years 1,029
Class IS  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 36
Expense Example, No Redemption, 3 Years 122
Expense Example, No Redemption, 5 Years 216
Expense Example, No Redemption, 10 Years $ 490