S000069099 [Member] Annual Total Returns |
12 Months Ended | ||||
|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| WESTERN ASSET SMASh SERIES CORE COMPLETION FUND | SMASh SERIES CORE COMPLETION FUND | |||||
| Prospectus [Line Items] | |||||
| Annual Return [Percent] | 5.25% | 7.00% | 3.29% | (32.17%) | (1.82%) |