Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 10,220	$ 19,175	$ 78,157	$ 90,863
Other comprehensive income (loss), net of tax:
Net unrealized gain (loss) in available-for-sale securities, net of tax expense (benefit) of $9,621, $(13,819), $6,674 and $(11,650)	27,265	(39,316)	18,597	(33,110)
Reclassification adjustment for loss on sale of securities included in net income, net of tax benefit of $10,467, $3,674, $14,692 and $3,674	29,698	10,426	41,686	10,426
Net unrealized loss in hedging activities, net of tax benefit of $21, $35, $151 and $99	(59)	(101)	(428)	(281)
Total other comprehensive income (loss), net of tax	56,904	(28,991)	59,855	(22,965)
Comprehensive income (loss) applicable to FB Financial Corporation and noncontrolling interest	67,124	(9,816)	138,012	67,898
Comprehensive income applicable to noncontrolling interest	0	0	8	8
Comprehensive income (loss) applicable to FB Financial Corporation	$ 67,124	$ (9,816)	$ 138,004	$ 67,890