Shareholder Report, Holdings (Details)	Aug. 31, 2025
C000005540 \| Maryland
Holdings [Line Items]
Percent of Net Asset Value	90.60%
C000005540 \| Puerto Rico
Holdings [Line Items]
Percent of Net Asset Value	5.30%
C000005540 \| District of Columbia
Holdings [Line Items]
Percent of Net Asset Value	3.10%
C000005540 \| South Carolina
Holdings [Line Items]
Percent of Net Asset Value	0.10%
C000005540 \| Other Holdings Grouping
Holdings [Line Items]
Percent of Net Asset Value	0.90%
C000005540 \| Housing Finance Revenue
Holdings [Line Items]
Percent of Net Asset Value	27.30%
C000005540 \| Hospital Revenue
Holdings [Line Items]
Percent of Net Asset Value	21.50%
C000005540 \| Genl Obligations - Local
Holdings [Line Items]
Percent of Net Asset Value	14.00%
C000005540 \| Ground Transportation Revenue
Holdings [Line Items]
Percent of Net Asset Value	10.20%
C000005540 \| Dedicated Tax Revenue
Holdings [Line Items]
Percent of Net Asset Value	7.20%
C000005540 \| Lease Revenue
Holdings [Line Items]
Percent of Net Asset Value	6.10%
C000005540 \| Educational Revenue
Holdings [Line Items]
Percent of Net Asset Value	4.50%
C000005540 \| Water & Sewer Revenue
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000005540 \| General Obligations - State
Holdings [Line Items]
Percent of Net Asset Value	2.20%
C000005540 \| Other 2
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000193179 \| Maryland
Holdings [Line Items]
Percent of Net Asset Value	90.60%
C000193179 \| Puerto Rico
Holdings [Line Items]
Percent of Net Asset Value	5.30%
C000193179 \| District of Columbia
Holdings [Line Items]
Percent of Net Asset Value	3.10%
C000193179 \| South Carolina
Holdings [Line Items]
Percent of Net Asset Value	0.10%
C000193179 \| Other Holdings Grouping
Holdings [Line Items]
Percent of Net Asset Value	0.90%
C000193179 \| Housing Finance Revenue
Holdings [Line Items]
Percent of Net Asset Value	27.30%
C000193179 \| Hospital Revenue
Holdings [Line Items]
Percent of Net Asset Value	21.50%
C000193179 \| Genl Obligations - Local
Holdings [Line Items]
Percent of Net Asset Value	14.00%
C000193179 \| Ground Transportation Revenue
Holdings [Line Items]
Percent of Net Asset Value	10.20%
C000193179 \| Dedicated Tax Revenue
Holdings [Line Items]
Percent of Net Asset Value	7.20%
C000193179 \| Lease Revenue
Holdings [Line Items]
Percent of Net Asset Value	6.10%
C000193179 \| Educational Revenue
Holdings [Line Items]
Percent of Net Asset Value	4.50%
C000193179 \| Water & Sewer Revenue
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000193179 \| General Obligations - State
Holdings [Line Items]
Percent of Net Asset Value	2.20%
C000193179 \| Other 2
Holdings [Line Items]
Percent of Net Asset Value	4.00%