v3.26.1
Average Annual Total Returns
12 Months Ended 42 Months Ended
Aug. 31, 2025
Dec. 31, 2024
Dec. 31, 2024
Nasdaq-100 Index® (reflects no deduction for fees, expenses or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent   25.88% 12.97%
S&P 500® Index (reflects no deduction for fees, expenses or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent   25.02% 11.93%
FT Vest Nasdaq-100 Buffer ETF - June      
Prospectus [Line Items]      
Average Annual Return, Percent   16.47% 10.27%
Performance Inception Date Jun. 18, 2021    
FT Vest Nasdaq-100 Buffer ETF - June | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent   16.47% 10.27%
FT Vest Nasdaq-100 Buffer ETF - June | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent   9.75% 8.05%