v3.26.1
Average Annual Total Returns
12 Months Ended 54 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% 16.96%
FT Vest U.S. Equity Buffer ETF - June      
Prospectus [Line Items]      
Average Annual Return, Percent   16.70% 12.45%
Performance Inception Date Jun. 19, 2020    
FT Vest U.S. Equity Buffer ETF - June | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent   16.70% 12.45%
FT Vest U.S. Equity Buffer ETF - June | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent   9.89% 9.92%