Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 124,571	$ 190,301	$ 63,629
Other comprehensive (loss) income, net of tax:
Net change in unrealized (loss) gain in available-for-sale securities, net of tax (benefits) expenses of $(62,316), $(7,224), and $5,781	(176,798)	(22,475)	18,430
Reclassification adjustment for gain on sale of securities included in net income, net of tax expenses of $—, $33 and $348	(1)	(93)	(987)
Net change in unrealized gain (loss) in hedging activities, net of tax expenses (benefits) of $532, $293 and $(363)	1,508	831	(1,031)
Reclassification adjustment for gain on hedging activities, net of tax expenses of $—, $— and $337	0	0	(955)
Total other comprehensive (loss) income, net of tax	(175,291)	(21,737)
Comprehensive (loss) income applicable to FB Financial Corporation and noncontrolling interest	(50,720)	168,564	79,086
Comprehensive income applicable to noncontrolling interest	16	16	8
Comprehensive (loss) income applicable to FB Financial Corporation	$ (50,736)	$ 168,548	$ 79,078