DWS Tax-Exempt Portfolio Average Annual Total Returns - Tax Free Investment Class [Member] - Tax-Free Investment Class - 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 | 2.73% | 1.30% | 0.86% | |
| Performance Inception Date | Mar. 19, 2007 |