Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income attributable to FB Financial Corporation and noncontrolling interest	$ 27,950	$ 36,381
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of fixed assets and software	2,841	2,228
Amortization of core deposit and other intangibles	789	990
Amortization of issuance costs on subordinated debt	96	97
Capitalization of mortgage servicing rights	(1,131)	(1,788)
Net change in fair value of mortgage servicing rights	(294)	5,274
Stock-based compensation expense	2,820	2,285
Provision for credit losses on loans HFI	1,852	4,997
Reversal of credit losses on unfunded commitments	(1,070)	(4,506)
Provision for mortgage loan repurchases	50	(250)
Accretion of discounts and premiums on acquired loans, net	(387)	(319)
Amortization of premiums and discounts on securities, net	1,356	1,382
Loss (gain) from investment securities, net	16,213	(69)
Originations of loans held for sale	(258,352)	(295,760)
Proceeds from sale of loans held for sale	251,548	340,108
Gain on sale and change in fair value of loans held for sale	(8,279)	(8,635)
Net (gain) loss on write-downs of other real estate owned and other assets	(565)	183
Provision for deferred income taxes	207	1,396
Earnings on bank-owned life insurance	(431)	(605)
Changes in:
Operating lease assets and liabilities, net	(207)	580
Other assets and interest receivable	(665)	62,512
Accrued expenses and other liabilities	1,927	(48,099)
Net cash provided by operating activities	36,268	98,382
Activity in available-for-sale securities:
Sales	207,882	0
Maturities, prepayments and calls	66,627	26,827
Purchases	(281,579)	(660)
Net change in loans	117,904	(52,540)
Proceeds from sales of FHLB stock, net	242	15,272
Purchases of premises and equipment	(1,620)	(9,450)
Proceeds from the sale of premises and equipment	137	0
Proceeds from the sale of other real estate owned	389	2,031
Proceeds from the sale of other assets	161	0
Proceeds from bank-owned life insurance	0	236
Net cash provided by (used in) investing activities	110,143	(18,284)
Cash flows from financing activities:
Net (decrease) increase in deposits	(47,856)	325,965
Net decrease in securities sold under agreements to repurchase and federal funds purchased	(30,535)	(48,815)
Net decrease in short-term FHLB advances and Bank Term Funding Program	0	(50,000)
Share based compensation withholding payments	(626)	(2,597)
Net proceeds from sale of common stock under employee stock purchase program	399	321
Repurchase of common stock	0	(4,944)
Dividends paid on common stock	(7,965)	(6,994)
Dividend equivalent payments made upon vesting of equity compensation	(30)	(135)
Net cash (used in) provided by financing activities	(86,613)	212,801
Net change in cash and cash equivalents	59,798	292,899
Cash and cash equivalents at beginning of the period	810,932	1,027,052
Cash and cash equivalents at end of the period	870,730	1,319,951
Supplemental cash flow information:
Interest paid	74,943	52,634
Taxes paid (refunded), net	277	(904)
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	753	235
Transfers from loans to other assets	1,031	0
Transfers from loans to loans held for sale	167	7,126
Transfers from loans held for sale to loans	40	776
Loans provided for sales of other assets	65	0
Decrease in rebooked GNMA loans under optional repurchase program	(353)	(5,683)
Trade date payable - securities	0	245
Dividends declared not paid on restricted stock units	87	48
Right-of-use assets obtained in exchange for operating lease liabilities	$ 0	$ 3,375