DWS Tax-Exempt Portfolio Average Annual Total Returns - Tax Exempt Cash Managed Shares [Member] - Tax-Exempt Cash Managed Shares - Return Before Taxes[Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended | |
|---|---|---|---|---|
Apr. 30, 2025 |
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
|
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 2.99% | 1.45% | 1.01% | |
| Performance Inception Date | Nov. 17, 1999 |