v3.25.2
S000014681 [Member] Investment Objectives and Goals - Western Asset SMASh Series M Fund
Feb. 28, 2025
Prospectus [Line Items]  
Risk/Return [Heading] Western Asset SMASh Series M Fund (“SMASh Series M Fund”)
Objective [Heading] Investment objective
Objective, Primary [Text Block]
The fund seeks to maximize total return consisting of capital appreciation and income, consistent with prudent investment management.