Shareholder Report, Holdings (Details) - C000007887 |
May 31, 2026 |
|---|---|
| Less than 1 Year | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| 1 to 3 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.00% |
| 3 to 5 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| 5 to 10 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.10% |
| 10 to 20 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.70% |
| 20 to 30 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 35.90% |
| Greater than 30 Years | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.10% |
| Other Line | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | (1.20%) |