v3.26.1
Average Annual Total Returns
12 Months Ended 19 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% 25.07%
FT Vest U.S. Equity Moderate Buffer ETF - May      
Prospectus [Line Items]      
Average Annual Return, Percent   12.34% 13.43%
Performance Inception Date May 19, 2023    
FT Vest U.S. Equity Moderate Buffer ETF - May | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent   12.34% 13.43%
FT Vest U.S. Equity Moderate Buffer ETF - May | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent   7.31% 10.32%