Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Interest income:
Interest and fees on loans	$ 626,402	$ 599,195	$ 436,363
Interest on investment securities
Taxable	50,057	27,257	25,469
Tax-exempt	4,749	7,153	7,332
Other	44,330	44,805	12,258
Total interest income	725,538	678,410	481,422
Interest expense:
Deposits	296,345	258,819	56,642
Borrowings	12,690	12,374	12,545
Total interest expense	309,035	271,193	69,187
Net interest income	416,503	407,217	412,235
Provision for credit losses on loans HFI	14,667	16,738	10,393
(Reversal of) provision for credit losses on unfunded commitments	(2,663)	(14,199)	8,589
Net interest income after provision for credit losses	404,499	404,678	393,253
Noninterest income:
Loss from investment securities, net	(56,378)	(13,973)	(376)
Loss on sales or write-downs of premises and equipment, other real estate owned and other assets, net	(2,167)	(27)	(265)
Other income	12,091	6,095	5,213
Total noninterest income	39,070	70,543	114,667
Noninterest expenses:
Salaries, commissions and employee benefits	183,813	203,441	211,491
Occupancy and equipment expense	26,250	28,148	23,562
Data processing	9,642	9,230	9,315
Legal and professional fees	7,679	8,890	15,028
Advertising	7,007	8,267	11,208
Amortization of core deposit and other intangibles	2,947	3,659	4,585
Mortgage restructuring expense	0	0	12,458
Other expense	59,561	63,294	60,699
Total noninterest expense	296,899	324,929	348,346
Income before income taxes	146,670	150,292	159,574
Income tax expense	30,619	30,052	35,003
Net income applicable to FB Financial Corporation and noncontrolling interest	116,051	120,240	124,571
Net income applicable to noncontrolling interest	16	16	16
Net income applicable to FB Financial Corporation	$ 116,035	$ 120,224	$ 124,555
Earnings per common share:
Basic (in dollars per share)	$ 2.48	$ 2.57	$ 2.64
Diluted (in dollars per share)	$ 2.48	$ 2.57	$ 2.64
Mortgage banking income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	$ 46,634	$ 44,692	$ 73,580
Investment services and trust income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	14,191	11,320	8,866
Service charges on deposit accounts
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	13,234	12,154	12,049
ATM and interchange fees
Noninterest income:
Mortgage banking income, service charges on deposit accounts, investment services and trust income, ATM and interchange fees	$ 11,465	$ 10,282	$ 15,600