v3.26.1
Fair Value Measurements (Details) - EBP 001 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value $ 137,838,445 $ 111,166,705
Cash    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 27,194 28,069
Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 136,578,705 110,103,346
FB Financial Corporation common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 1,232,546 1,035,290
Level 1, Level 2, and Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 137,838,445 111,166,705
Level 1, Level 2, and Level 3 | Cash    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 27,194 28,069
Level 1, Level 2, and Level 3 | Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 136,578,705 110,103,346
Level 1, Level 2, and Level 3 | FB Financial Corporation common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 1,232,546 1,035,290
Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 137,838,445 111,166,705
Level 1 | Cash    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 27,194 28,069
Level 1 | Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 136,578,705 110,103,346
Level 1 | FB Financial Corporation common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 1,232,546 1,035,290
Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 2 | Cash    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 2 | Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 2 | FB Financial Corporation common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 3 | Cash    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 3 | Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value 0 0
Level 3 | FB Financial Corporation common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments at fair value $ 0 $ 0