Vanguard Municipal Money Market Fund Average Annual Total Returns - Retail Prospectus [Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Tax-Exempt Money Market Funds Average[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 2.28% | 1.79% | 1.19% |
| Investor Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 2.66% | 2.05% | 1.45% |