v3.25.1
Shareholder Report, Line Graph (Details) - USD ($)
 12 Months Ended 60 Months Ended 120 Months Ended
Mar. 31, 2025
Mar. 31, 2025
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Mar. 31, 2022
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Mar. 31, 2015
C000079007 [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name with Maximum Sales Charge - 2.50%                        
Account Value $ 10,617 $ 10,617 $ 10,617 $ 10,314 $ 10,116 $ 10,054 $ 10,436 $ 10,177 $ 10,047 $ 9,834 $ 9,840 $ 9,845 $ 9,753
Average Annual Return, Percent 0.40% 0.34% 0.60%                    
C000079007 [Member] | Without Sales Load [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name without Sales Charge                        
Average Annual Return, Percent 2.95% 0.85% 0.85%                    
C000000147 [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name Class D                        
Account Value $ 11,050 $ 11,050 $ 11,050 10,719 10,498 10,418 10,797 10,513 10,364 10,121 10,113 10,110 10,000
Average Annual Return, Percent 3.10% 1.00% 1.00%                    
C000073380 [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name Class I                        
Account Value $ 11,160 $ 11,160 $ 11,160 10,814 10,580 10,498 10,860 10,565 10,404 10,159 10,140 10,120 10,000
Average Annual Return, Percent 3.20% 1.10% 1.10%                    
C000130293 [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name Class Y                        
Account Value $ 1,114,400 $ 1,114,400 $ 1,114,400 1,079,061 1,054,825 1,046,824 1,083,075 1,054,366 1,037,350 1,015,989 1,014,096 1,012,062 1,000,000
Average Annual Return, Percent 3.27% 1.11% 1.09%                    
Bloomberg U S Municipal Bond Index [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name Bloomberg U.S. Municipal Bond Index (broad-based index)                        
Account Value [1] $ 12,341 $ 12,341 $ 12,341 12,193 11,823 11,792 12,344 11,699 11,266 10,691 10,414 10,398 10,000
Average Annual Return, Percent [1] 1.22% 1.07% 2.13%                    
Bloomberg Municipal Bond 1 3 Year Blend Index [Member]                          
Account Value [Line Items]                          
Line Graph and Table Measure Name Bloomberg Municipal Bond 1-3 Year Blend Index                        
Account Value $ 11,495 $ 11,495 $ 11,495 $ 11,109 $ 10,888 $ 10,726 $ 11,022 $ 10,709 $ 10,515 $ 10,238 $ 10,188 $ 10,125 $ 10,000
Average Annual Return, Percent 3.48% 1.43% 1.40%                    
[1] In accordance with regulatory changes requiring the Fund’s primary benchmark to represent the overall applicable market, the Fund’s primary prospectus benchmark changed to the indicated benchmark effective as of March 31, 2025.