Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Total common shareholders' equity	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss), net	Noncontrolling interests
Beginning balance at Dec. 31, 2020	$ 1,291,382	$ 1,291,289	$ 47,222	$ 898,847	$ 317,625	$ 27,595	$ 93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to FB Financial Corporation and noncontrolling interest	52,874	52,874			52,874
Other comprehensive loss, net of taxes	(11,537)	(11,537)				(11,537)
Stock based compensation expense	2,666	2,666	3	2,663
Restricted stock units vested and distributed, net of shares withheld	(1,715)	(1,715)	85	(1,800)
Shares issued under employee stock purchase program	833	833	22	811
Dividends declared	(5,307)	(5,307)			(5,307)
Noncontrolling interest distribution	0
Ending balance at Mar. 31, 2021	1,329,196	1,329,103	47,332	900,521	365,192	16,058	93
Beginning balance at Dec. 31, 2021	1,432,695	1,432,602	47,549	892,529	486,666	5,858	93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to FB Financial Corporation and noncontrolling interest	35,236	35,236			35,236
Other comprehensive loss, net of taxes	(77,402)	(77,402)				(77,402)
Repurchase of common stock	(6,203)	(6,203)	(145)	(6,058)
Stock based compensation expense	2,582	2,582	1	2,581
Restricted stock units vested and distributed, net of shares withheld	(1,488)	(1,488)	68	(1,556)
Shares issued under employee stock purchase program	687	687	15	672
Dividends declared	(6,238)	(6,238)			(6,238)
Noncontrolling interest distribution	0
Ending balance at Mar. 31, 2022	$ 1,379,869	$ 1,379,776	$ 47,488	$ 888,168	$ 515,664	$ (71,544)	$ 93