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DWS Government and Agency Securities Portfolio Average Annual Total Returns - DWS Gov and Agcy Money Fund [Member] - DWS Government and Agency Money Fund - Return Before Taxes[Member]
12 Months Ended 60 Months Ended 120 Months Ended
Jul. 28, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Prospectus [Line Items]        
Average Annual Return, Percent   4.20% 3.16% 2.07%
Performance Inception Date Mar. 19, 2007