DWS Treasury Portfolio Expense Example - Investment Class Shares [Member] - DWS Treasury Portfolio - Investment Class Shares	Jul. 28, 2026 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 59
Expense Example, with Redemption, 3 Years	186
Expense Example, with Redemption, 5 Years	324
Expense Example, with Redemption, 10 Years	$ 726

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