Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest income:
Interest and fees on loans	$ 599,195	$ 436,363	$ 359,262
Interest on investment securities
Taxable	27,257	25,469	15,186
Tax-exempt	7,153	7,332	7,657
Other	44,805	12,258	2,893
Total interest income	678,410	481,422	384,998
Interest expense:
Deposits	258,819	56,642	30,189
Borrowings	12,374	12,545	7,439
Total interest expense	271,193	69,187	37,628
Net interest income	407,217	412,235	347,370
Provision for (reversal of) credit losses on loans HFI	16,738	10,393	(38,995)
(Reversal of) provision for credit losses on unfunded commitments	(14,199)	8,589	(1,998)
Net interest income after provision for (reversal of) credit losses	404,678	393,253	388,363
Noninterest income:
(Loss) gain from investment securities, net	(13,973)	(376)	324
(Loss) gain on sales or write-downs of other real estate owned and other assets	(27)	(265)	2,827
Other income	6,095	5,213	19,047
Total noninterest income	70,543	114,667	228,255
Noninterest expenses:
Salaries, commissions and employee benefits	203,441	211,491	248,318
Occupancy and equipment expense	28,148	23,562	22,733
Data processing	9,230	9,315	9,987
Legal and professional fees	8,890	15,028	9,161
Advertising	8,267	11,208	13,921
Amortization of core deposit and other intangibles	3,659	4,585	5,473
Mortgage restructuring expense	0	12,458	0
Other expense	63,294	60,699	63,974
Total noninterest expense	324,929	348,346	373,567
Income before income taxes	150,292	159,574	243,051
Income tax expense	30,052	35,003	52,750
Net income applicable to FB Financial Corporation and noncontrolling interest	120,240	124,571	190,301
Net income applicable to noncontrolling interest	16	16	16
Net income applicable to FB Financial Corporation	$ 120,224	$ 124,555	$ 190,285
Earnings per common share:
Basic (in dollars per share)	$ 2.57	$ 2.64	$ 4.01
Diluted (in dollars per share)	$ 2.57	$ 2.64	$ 3.97
Mortgage banking income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	$ 44,692	$ 73,580	$ 167,565
Service charges on deposit accounts
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	12,154	12,049	10,034
Investment services and trust income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	11,320	8,866	8,558
ATM and interchange fees
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	$ 10,282	$ 15,600	$ 19,900