v3.25.2
S000000716 [Member] Performance Management - Western Asset High Yield Fund
May 31, 2025
Prospectus [Line Items]  
Bar Chart and Performance Table [Heading] Performance
Performance Narrative [Text Block]
The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class I shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of a broad measure of market performance and an additional index with characteristics relevant to the fund. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ. The fund makes updated performance information, including its current net asset value, available at www.franklintempleton.com/prospectus (select fund and share class), or by calling the fund at 877‑6LM‑FUND/656‑3863.
The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.
Performance Past Does Not Indicate Future [Text] The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Performance Information Illustrates Variability of Returns [Text] The bar chart shows changes in the fund’s performance from year to year for Class I shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of a broad measure of market performance and an additional index with characteristics relevant to the fund.
Bar Chart Does Not Reflect Sales Loads [Text] Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.
Bar Chart [Heading] Total returns (%) Before taxes
Bar Chart Closing [Text Block] Calendar Years ended December 31 Best Quarter (06/30/2020): 10.92 Worst Quarter (03/31/2020): (14.24) The year-to-date return as of the most recent calendar quarter, which ended June 30, 2025, was 4.69
Performance Table Heading Average annual total returns (%)1(for periods ended December 31, 2024)
Performance Table Narrative
No one index is representative of the fund’s portfolio.
The after-tax returns are shown only for Class I shares, are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I.
Important data provider notices and terms are available at www.franklintempletondatasources.com. Such information is subject to change.
Performance Table Uses Highest Federal Rate The after-tax returns are shown only for Class I shares, are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text] The after-tax returns are shown only for Class I shares, are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I.
Performance Availability Website Address [Text] www.franklintempleton.com/prospectus (select fund and share class)
Performance Availability Phone [Text] 877‑6LM‑FUND/656‑3863
Class I  
Prospectus [Line Items]  
Year to Date Return, Label [Optional Text] year-to-date return
Bar Chart, Year to Date Return 4.69%
Bar Chart, Year to Date Return, Date Jun. 30, 2025
Highest Quarterly Return, Label [Optional Text] Best Quarter 
Highest Quarterly Return 10.92%
Highest Quarterly Return, Date Jun. 30, 2020
Lowest Quarterly Return, Label [Optional Text] Worst Quarter 
Lowest Quarterly Return (14.24%)
Lowest Quarterly Return, Date Mar. 31, 2020