Shareholder Report, Holdings (Details)	May 31, 2026
C000007969 \| Less than 1 Year
Holdings [Line Items]
Percent of Net Asset Value	7.40%
C000007969 \| 1 to 3 Years
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000007969 \| 3 to 5 Years
Holdings [Line Items]
Percent of Net Asset Value	3.70%
C000007969 \| 5 to 10 Years
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000007969 \| 10 to 20 Years
Holdings [Line Items]
Percent of Net Asset Value	38.40%
C000007969 \| 20 to 30 Years
Holdings [Line Items]
Percent of Net Asset Value	32.40%
C000007969 \| Greater than 30 Years
Holdings [Line Items]
Percent of Net Asset Value	5.10%
C000007969 \| Other Line
Holdings [Line Items]
Percent of Net Asset Value	0.00%
C000007970 \| Less than 1 Year
Holdings [Line Items]
Percent of Net Asset Value	7.40%
C000007970 \| 1 to 3 Years
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000007970 \| 3 to 5 Years
Holdings [Line Items]
Percent of Net Asset Value	3.70%
C000007970 \| 5 to 10 Years
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000007970 \| 10 to 20 Years
Holdings [Line Items]
Percent of Net Asset Value	38.40%
C000007970 \| 20 to 30 Years
Holdings [Line Items]
Percent of Net Asset Value	32.40%
C000007970 \| Greater than 30 Years
Holdings [Line Items]
Percent of Net Asset Value	5.10%
C000007970 \| Other Line
Holdings [Line Items]
Percent of Net Asset Value	0.00%
C000007971 \| Other Line
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000007971 \| 1 to 7 Days
Holdings [Line Items]
Percent of Net Asset Value	93.00%
C000007971 \| 8 to 30 Days
Holdings [Line Items]
Percent of Net Asset Value	1.10%
C000007971 \| 31 to 60 Days
Holdings [Line Items]
Percent of Net Asset Value	0.70%
C000007971 \| 61 to 90 Days
Holdings [Line Items]
Percent of Net Asset Value	1.70%
C000007971 \| 91 to 180 Days
Holdings [Line Items]
Percent of Net Asset Value	1.50%
C000007971 \| Over 180 Days
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000260432 \| Less than 1 Year
Holdings [Line Items]
Percent of Net Asset Value	4.90%
C000260432 \| 1 to 3 Years
Holdings [Line Items]
Percent of Net Asset Value	7.10%
C000260432 \| 3 to 5 Years
Holdings [Line Items]
Percent of Net Asset Value	8.10%
C000260432 \| 5 to 10 Years
Holdings [Line Items]
Percent of Net Asset Value	20.50%
C000260432 \| 10 to 20 Years
Holdings [Line Items]
Percent of Net Asset Value	33.80%
C000260432 \| 20 to 30 Years
Holdings [Line Items]
Percent of Net Asset Value	23.20%
C000260432 \| Greater than 30 Years
Holdings [Line Items]
Percent of Net Asset Value	3.60%
C000260432 \| Other Line
Holdings [Line Items]
Percent of Net Asset Value	(1.20%)