v3.26.1
Shareholder Report, Holdings (Details)
Jun. 30, 2026
C000024678 [Member] | Senior Care [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000024678 [Member] | Water And Sewer [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
C000024678 [Member] | Toll Road [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
C000024678 [Member] | Airport [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90%
C000024678 [Member] | Hospital [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
C000024678 [Member] | Prepaid Gas Utility [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000024678 [Member] | Electric And Gas [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000024678 [Member] | Multifamily [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
C000024678 [Member] | General Obligation Local [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
C000024678 [Member] | General Obligation State [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80%
C000024678 [Member] | Industrial Development Bond Pollution Control Revenue [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000024677 [Member] | Senior Care [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000024677 [Member] | Water And Sewer [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
C000024677 [Member] | Toll Road [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
C000024677 [Member] | Airport [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90%
C000024677 [Member] | Hospital [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
C000024677 [Member] | Prepaid Gas Utility [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000024677 [Member] | Electric And Gas [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000024677 [Member] | Multifamily [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
C000024677 [Member] | General Obligation Local [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
C000024677 [Member] | General Obligation State [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80%
C000024677 [Member] | Industrial Development Bond Pollution Control Revenue [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000037571 [Member] | Senior Care [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000037571 [Member] | Water And Sewer [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
C000037571 [Member] | Toll Road [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
C000037571 [Member] | Airport [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.90%
C000037571 [Member] | Hospital [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
C000037571 [Member] | Prepaid Gas Utility [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000037571 [Member] | Electric And Gas [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000037571 [Member] | Multifamily [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
C000037571 [Member] | General Obligation Local [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
C000037571 [Member] | General Obligation State [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.80%
C000037571 [Member] | Industrial Development Bond Pollution Control Revenue [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%