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% 22.27%
FT Vest U.S. Equity Moderate Buffer ETF - June      
Prospectus [Line Items]      
Average Annual Return, Percent   13.30% 12.92%
Performance Inception Date Jun. 16, 2023    
FT Vest U.S. Equity Moderate Buffer ETF - June | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent   13.30% 12.92%
FT Vest U.S. Equity Moderate Buffer ETF - June | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent   7.87% 9.92%