v3.25.2
DWS Treasury Portfolio Average Annual Total Returns - Institutional Shares [Member] - Institutional Shares - Return Before Taxes[Member]
12 Months Ended 60 Months Ended 120 Months Ended
Mar. 31, 2025
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Prospectus [Line Items]        
Average Annual Return, Percent   5.15% 2.40% 1.68%
Performance Inception Date Dec. 17, 1991