v3.25.4
First Trust Institutional Preferred Securities and Income ETF Average Annual Total Returns
 12 Months Ended 60 Months Ended 100 Months Ended 120 Months Ended 155 Months Ended
Oct. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
FPEI Blended Benchmark (reflects no deduction for fees, expenses or taxes)[Member]            
Prospectus [Line Items]            
Average Annual Return, Percent [1]   9.43% 3.42% 4.77%    
ICE BofA US Investment Grade Institutional Capital Securities Index (reflects no deduction for fees, expenses or taxes)[Member]            
Prospectus [Line Items]            
Average Annual Return, Percent   8.64% 3.77% 4.89% 5.49% 5.37%
Bloomberg US Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)[Member]            
Prospectus [Line Items]            
Average Annual Return, Percent   7.30% (0.36%) 1.71% 2.01% 1.94%
First Trust Institutional Preferred Securities and Income ETF            
Prospectus [Line Items]            
Average Annual Return, Percent   9.92% 4.55% 5.05%    
Performance Inception Date Aug. 22, 2017          
First Trust Institutional Preferred Securities and Income ETF | After Taxes on Distributions            
Prospectus [Line Items]            
Average Annual Return, Percent   7.38% 2.29% 2.81%    
First Trust Institutional Preferred Securities and Income ETF | After Taxes on Distributions and Sales            
Prospectus [Line Items]            
Average Annual Return, Percent   5.80% 2.46% 2.86%    
[1] The Blended Benchmark consists of a 45/40/15 blend of the ICE BofA US Investment Grade Institutional Capital Securities Index, the ICE USD Contingent Capital Index and the ICE BofA US High Yield Institutional Capital Securities Index.