v3.26.3
FT Vest Emerging Markets Buffer ETF - December Average Annual Total Returns
12 Months Ended 15 Months Ended
May 31, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
MSCI Emerging Markets Index (reflects no deduction for fees, expenses or taxes)[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent   32.90% 33.57% 22.83%
FT Vest Emerging Markets Buffer ETF - December        
Prospectus [Line Items]        
Average Annual Return, Percent   20.33% 21.43%  
Performance Inception Date Dec. 20, 2024      
FT Vest Emerging Markets Buffer ETF - December | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent   20.33% 21.43%  
FT Vest Emerging Markets Buffer ETF - December | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent   15.50% 12.69%