v3.25.3
Shareholder Report, Holdings (Details)
Aug. 31, 2025
C000005558 | Puerto Rico  
Holdings [Line Items]  
Percent of Net Asset Value 10.90%
C000005558 | California  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000005558 | Texas  
Holdings [Line Items]  
Percent of Net Asset Value 6.50%
C000005558 | Florida  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
C000005558 | Wisconsin  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
C000005558 | Pennsylvania  
Holdings [Line Items]  
Percent of Net Asset Value 4.90%
C000005558 | Maryland  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
C000005558 | Ohio  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
C000005558 | Illinois  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000005558 | Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value 45.30%
C000005558 | Life Care/Nursing Home Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 21.50%
C000005558 | Ground Transportation Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
C000005558 | Educational Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
C000005558 | Dedicated Tax Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 8.60%
C000005558 | Housing Finance Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
C000005558 | Industrial & Pollution Control Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
C000005558 | General Obligations - State  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
C000005558 | Water & Sewer Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000005558 | General Obligations - Local  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000005558 | Other 2  
Holdings [Line Items]  
Percent of Net Asset Value 24.20%
C000117193 | Puerto Rico  
Holdings [Line Items]  
Percent of Net Asset Value 10.90%
C000117193 | California  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000117193 | Texas  
Holdings [Line Items]  
Percent of Net Asset Value 6.50%
C000117193 | Florida  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
C000117193 | Wisconsin  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
C000117193 | Pennsylvania  
Holdings [Line Items]  
Percent of Net Asset Value 4.90%
C000117193 | Maryland  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
C000117193 | Ohio  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
C000117193 | Illinois  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000117193 | Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value 45.30%
C000117193 | Life Care/Nursing Home Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 21.50%
C000117193 | Ground Transportation Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
C000117193 | Educational Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
C000117193 | Dedicated Tax Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 8.60%
C000117193 | Housing Finance Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
C000117193 | Industrial & Pollution Control Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
C000117193 | General Obligations - State  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
C000117193 | Water & Sewer Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000117193 | General Obligations - Local  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000117193 | Other 2  
Holdings [Line Items]  
Percent of Net Asset Value 24.20%
C000177208 | Puerto Rico  
Holdings [Line Items]  
Percent of Net Asset Value 10.90%
C000177208 | California  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000177208 | Texas  
Holdings [Line Items]  
Percent of Net Asset Value 6.50%
C000177208 | Florida  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
C000177208 | Wisconsin  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
C000177208 | Pennsylvania  
Holdings [Line Items]  
Percent of Net Asset Value 4.90%
C000177208 | Maryland  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
C000177208 | Ohio  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
C000177208 | Illinois  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000177208 | Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value 45.30%
C000177208 | Life Care/Nursing Home Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 21.50%
C000177208 | Ground Transportation Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
C000177208 | Educational Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
C000177208 | Dedicated Tax Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 8.60%
C000177208 | Housing Finance Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
C000177208 | Industrial & Pollution Control Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
C000177208 | General Obligations - State  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
C000177208 | Water & Sewer Revenue  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000177208 | General Obligations - Local  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000177208 | Other 2  
Holdings [Line Items]  
Percent of Net Asset Value 24.20%