Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 116,051	$ 120,240	$ 124,571
Other comprehensive income (loss), net of tax:
Net unrealized (loss) gain in available-for-sale securities, net of tax (benefit) expense of $(2,744), $8,706 and $(62,316)	(8,217)	24,802	(176,798)
Reclassification adjustment for loss (gain) on sale of securities included in net income, net of tax benefit of $14,692, $3,668 and $—	41,686	10,406	(1)
Net unrealized (loss) gain in hedging activities, net of tax (benefit) expense of $(151), $(176), and $532	428	500	(1,508)
Total other comprehensive income (loss), net of tax	33,041	34,708	(175,291)
Comprehensive income (loss) applicable to FB Financial Corporation and noncontrolling interest	149,092	154,948	(50,720)
Comprehensive income applicable to noncontrolling interest	16	16	16
Comprehensive income (loss) applicable to FB Financial Corporation	$ 149,076	$ 154,932	$ (50,736)