DWS Tax-Exempt Portfolio Average Annual Total Returns - DWS Tax Exempt Money Fund [Member] - DWS Tax-Exempt Money Fund - 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 | 3.11% | 1.54% | 1.12% | |
| Performance Inception Date | Mar. 19, 2007 |