010001 - Document - Document And Entity Information {Elements} link:presentationLink link:calculationLink link:definitionLink 040014 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class A_TSR SemiAnnual {Class A} link:presentationLink link:calculationLink link:definitionLink 040015 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class A_TSR SemiAnnual {Class A} link:presentationLink link:calculationLink link:definitionLink 040016 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class A_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink 040018 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class C_TSR SemiAnnual {Class C} link:presentationLink link:calculationLink link:definitionLink 040019 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class C_TSR SemiAnnual {Class C} link:presentationLink link:calculationLink link:definitionLink 040020 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class C_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink 040022 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class C1_TSR SemiAnnual {Class C1} link:presentationLink link:calculationLink link:definitionLink 040023 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class C1_TSR SemiAnnual {Class C1} link:presentationLink link:calculationLink link:definitionLink 040024 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class C1_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink 040026 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class FI_TSR SemiAnnual {Class FI} link:presentationLink link:calculationLink link:definitionLink 040027 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class FI_TSR SemiAnnual {Class FI} link:presentationLink link:calculationLink link:definitionLink 040028 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class FI_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink 040030 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class R_TSR SemiAnnual {Class R} link:presentationLink link:calculationLink link:definitionLink 040031 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class R_TSR SemiAnnual {Class R} link:presentationLink link:calculationLink link:definitionLink 040032 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class R_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink 040034 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class I_TSR SemiAnnual {Class I} link:presentationLink link:calculationLink link:definitionLink 040035 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class I_TSR SemiAnnual {Class I} link:presentationLink link:calculationLink link:definitionLink 040036 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class I_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink 040038 - Document - Shareholder Report, Line Graph (Details) LMF1900_Western Asset Core Bond Fund_Class IS_TSR SemiAnnual {Class IS} link:presentationLink link:calculationLink link:definitionLink 040039 - Document - Shareholder Report, Average Annual Return (Details) LMF1900_Western Asset Core Bond Fund_Class IS_TSR SemiAnnual {Class IS} link:presentationLink link:calculationLink link:definitionLink 040040 - Document - Shareholder Report, Holdings (Details) LMF1900_Western Asset Core Bond Fund_Class IS_TSR SemiAnnual {Elements} link:presentationLink link:calculationLink link:definitionLink