Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	RSUs	PSUs	Total common shareholders' equity	Total common shareholders' equity RSUs	Total common shareholders' equity PSUs	Common stock	Common stock RSUs	Common stock PSUs	Additional paid-in capital	Additional paid-in capital RSUs	Additional paid-in capital PSUs	Retained earnings	Accumulated other comprehensive loss, net	Noncontrolling interest
Beginning balance at Dec. 31, 2022	$ 1,325,518			$ 1,325,425			$ 46,738			$ 861,588			$ 586,532	$ (169,433)	$ 93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to FB Financial Corporation and noncontrolling interest	36,381			36,381									36,381
Other comprehensive income (loss), net of taxes	19,867			19,867										19,867
Repurchase of common stock	(4,944)			(4,944)			(136)			(4,808)
Stock based compensation expense	2,285			2,285			1			2,284
Restricted stock and performance-based restricted stock units vested, net of taxes		$ (1,452)	$ (1,145)		$ (1,452)	$ (1,145)		$ 92	$ 60		$ (1,544)	$ (1,205)
Shares issued under employee stock purchase program	321			321			8			313
Dividends declared	(7,042)			(7,042)									(7,042)
Ending balance at Mar. 31, 2023	1,369,789			1,369,696			46,763			856,628			615,871	(149,566)	93
Beginning balance at Dec. 31, 2023	1,454,887			1,454,794			46,849			864,258			678,412	(134,725)	93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to FB Financial Corporation and noncontrolling interest	27,950			27,950									27,950
Other comprehensive income (loss), net of taxes	2,241			2,241										2,241
Stock based compensation expense	2,820			2,820			1			2,819
Restricted stock and performance-based restricted stock units vested, net of taxes		$ (281)	$ (345)		$ (281)	$ (345)		$ 11	$ 25		$ (292)	$ (370)
Shares issued under employee stock purchase program	399			399			11			388
Dividends declared	(8,052)			(8,052)									(8,052)
Ending balance at Mar. 31, 2024	$ 1,479,619			$ 1,479,526			$ 46,897			$ 866,803			$ 698,310	$ (132,484)	$ 93