v3.26.1
Average Annual Total Returns
12 Months Ended 53 Months Ended
Aug. 31, 2025
Dec. 31, 2024
Dec. 31, 2024
S&P 500® Index (reflects no deduction for fees, expenses or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent   25.02% 16.20%
FT Vest U.S. Equity Buffer ETF - July      
Prospectus [Line Items]      
Average Annual Return, Percent   17.73% 11.44%
Performance Inception Date Jul. 17, 2020    
FT Vest U.S. Equity Buffer ETF - July | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent   17.73% 11.44%
FT Vest U.S. Equity Buffer ETF - July | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent   10.49% 9.08%