Vanguard Municipal Low Duration Fund Average Annual Total Returns - Investor Prospectus [Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
|
| Short Municipal Debt Funds Average[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 2.87% | 1.24% | 1.18% |
| Bloomberg Municipal Bond Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 1.05% | 0.99% | 2.25% |
| Investor Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 3.29% | 1.64% | 1.23% |
| Investor Shares | After Taxes on Distributions | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 3.29% | 1.24% | 0.86% |
| Investor Shares | After Taxes on Distributions and Sales | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 3.29% | 1.24% | 0.86% |