v3.25.4
First Trust Managed Municipal Fund Average Annual Total Returns
 10 Months Ended 12 Months Ended 43 Months Ended
Oct. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Bloomberg Municipal Bond 5-15 Year Index (reflects no deduction for fees, expenses or taxes)[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent [1]     5.73% 3.99%
Performance Inception Date [1] Jun. 15, 2022      
Bloomberg Municipal Bond Index (reflects no deduction for fees, expenses or taxes)[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent [1]     4.25% 3.77%
Performance Inception Date [1] Jun. 15, 2022      
A | Return Before Taxes[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent [2]    
Performance Inception Date [2] Mar. 04, 2025      
I | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent     3.81% 3.94%
Performance Inception Date Jun. 15, 2022      
I | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent     3.77% 3.81%
Performance Inception Date Jun. 15, 2022      
I | Return Before Taxes[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent     3.81% 3.94%
Performance Inception Date Jun. 15, 2022      
[1] Since inception return is based on the Class I Shares inception date.
[2] Because Class A shares had an inception date of March 4, 2025, performance data is not available for any of the periods indicated above.