Consolidated statements of income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest income:
Interest and fees on loans	$ 359,262	$ 294,596	$ 260,458
Interest on securities
Taxable	15,186	10,267	13,223
Tax-exempt	7,657	7,076	4,805
Other	2,893	2,705	4,051
Total interest income	384,998	314,644	282,537
Interest expense:
Deposits	30,189	42,859	51,568
Borrowings	7,439	6,127	4,933
Total interest expense	37,628	48,986	56,501
Net interest income	347,370	265,658	226,036
Provision for credit losses	(38,995)	94,606	7,053
Provision for credit losses on unfunded commitments	(1,998)	13,361	0
Net interest income after provisions for credit losses	388,363	157,691	218,983
Noninterest income:
Gain from securities, net	324	1,631	57
Gain (loss) on sales or write-downs of other real estate owned	2,504	(1,491)	545
Gain (loss) from other assets	323	(90)	(104)
Other income	19,047	15,322	7,099
Total noninterest income	228,255	301,855	135,397
Noninterest expenses:
Salaries, commissions and employee benefits	248,318	233,768	152,084
Occupancy and equipment expense	22,733	18,979	15,641
Legal and professional fees	9,161	7,654	7,486
Data processing	9,987	11,390	10,589
Merger costs	0	34,879	5,385
Amortization of core deposit and other intangibles	5,473	5,323	4,339
Advertising	13,921	10,062	9,138
Other expense	63,974	55,030	40,179
Total noninterest expense	373,567	377,085	244,841
Income before income taxes	243,051	82,461	109,539
Income tax expense	52,750	18,832	25,725
Net income applicable to FB Financial Corporation and noncontrolling interest	190,301	63,629	83,814
Net income applicable to noncontrolling interest	16	8	0
Net income applicable to FB Financial Corporation	$ 190,285	$ 63,621	$ 83,814
Earnings per common share
Basic (in dollars per share)	$ 4.01	$ 1.69	$ 2.70
Diluted (in dollars per share)	$ 3.97	$ 1.67	$ 2.65
Mortgage banking income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 167,565	$ 255,328	$ 100,916
Service charges on deposit accounts
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	10,034	9,160	9,479
ATM and interchange fees
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	19,900	14,915	12,161
Investment services and trust income
Noninterest income:
Mortgage banking income, service charges on deposit accounts, ATM and interchange fees, investment services and trust income	$ 8,558	$ 7,080	$ 5,244