v3.25.2
Shareholder Report, Average Annual Return (Details)
 12 Months Ended 60 Months Ended 120 Months Ended
Apr. 30, 2025
Apr. 30, 2025
Apr. 30, 2025
Class A      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A (with sales charge)    
Average Annual Return, Percent (1.63%) 0.34% 1.26%
Class A1      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A1 (with sales charge)    
Average Annual Return, Percent (1.53%) 0.50% 1.36%
Class C      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class C (with sales charge)    
Average Annual Return, Percent 0.81% 0.71% 1.19%
Class R6      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class R6    
Average Annual Return, Percent 2.50% 1.41% 1.85%
Advisor Class      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Advisor Class    
Average Annual Return, Percent 2.45% 1.37% 1.85%
Without Sales Load [Member] | Class A      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A    
Average Annual Return, Percent 2.20% 1.11% 1.65%
Without Sales Load [Member] | Class A1      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class A1    
Average Annual Return, Percent 2.35% 1.27% 1.75%
Without Sales Load [Member] | Class C      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class C    
Average Annual Return, Percent 1.79% 0.71% 1.19%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 1.66% 1.17% 2.10%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 1.66% 1.17% 2.10%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 1.66% 1.17% 2.10%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 1.66% 1.17% 2.10%
Bloomberg Municipal Bond Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg Municipal Bond Index    
Average Annual Return, Percent 1.66% 1.17% 2.10%