Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 120,240	$ 124,571	$ 190,301
Other comprehensive income (loss), net of tax:
Net unrealized gain (loss) in available-for-sale securities, net of tax expense (benefit) of $8,706, $(62,316), and $(7,224)	24,802	(176,798)	(22,475)
Reclassification adjustment for loss (gain) on sale of securities included in net income, net of tax benefit (expense) of $3,668, $—, and $(33)	10,406	(1)	(93)
Net unrealized (loss) gain in hedging activities, net of tax (benefit) expense of $(176), $532, and $293	(500)	1,508	831
Total other comprehensive income (loss), net of tax	34,708	(175,291)	(21,737)
Comprehensive income (loss) applicable to FB Financial Corporation and noncontrolling interest	154,948	(50,720)	168,564
Comprehensive income applicable to noncontrolling interest	16	16	16
Comprehensive income (loss) applicable to FB Financial Corporation	$ 154,932	$ (50,736)	$ 168,548