v3.25.2
S000005562 [Member] Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended 131 Months Ended 311 Months Ended 329 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
S&P Municipal Bond Index (reflects no deduction for fees, expenses or taxes)            
Prospectus [Line Items]            
Average Annual Return, Percent [1] 1.90% 1.20% 2.34%      
S&P Municipal Bond Intermediate Index (reflects no deduction for fees, expenses or taxes)            
Prospectus [Line Items]            
Average Annual Return, Percent [2] 1.09% 1.11% 2.20%      
Lipper Other States Municipal Debt Funds Classification Average (reflects no deduction for taxes or sales loads)            
Prospectus [Line Items]            
Average Annual Return, Percent [3] 0.75% 0.39% 1.34%      
Class A            
Prospectus [Line Items]            
Average Annual Return, Percent (2.05%) (0.08%) 1.20%      
Performance Inception Date         Feb. 01, 1999  
Class A | After Taxes on Distributions            
Prospectus [Line Items]            
Average Annual Return, Percent (2.05%) (0.08%) 1.20%      
Performance Inception Date         Feb. 01, 1999  
Class A | After Taxes on Distributions and Sales            
Prospectus [Line Items]            
Average Annual Return, Percent (0.16%) 0.42% 1.42%      
Performance Inception Date         Feb. 01, 1999  
Class I            
Prospectus [Line Items]            
Average Annual Return, Percent 1.23% 0.72% 1.72%      
Performance Inception Date           Aug. 08, 1997
Class C            
Prospectus [Line Items]            
Average Annual Return, Percent 0.12% (0.29%) 0.86%      
Performance Inception Date       Feb. 10, 2014    
[1]
An index designed to measure the performance of the tax-exempt U.S. municipal bond market.
[2]
An index containing bonds in the S&P Municipal Bond Index that mature between 3 and 15 years.
[3]
Represents the average annualized total return for all reporting funds in the Lipper Other States Municipal Debt Funds Classification.