S000069099 [Member] Expense Example - WESTERN ASSET SMASh SERIES CORE COMPLETION FUND - SMASh SERIES CORE COMPLETION FUND	Feb. 28, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 0
Expense Example, with Redemption, 3 Years	18
Expense Example, with Redemption, 5 Years	37
Expense Example, with Redemption, 10 Years	$ 94

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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