Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cash flows from operating activities:
Net income attributable to FB Financial Corporation and noncontrolling interest	$ 39,361	$ 27,950
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of fixed assets and software	2,767	2,841
Amortization of core deposit and other intangibles	656	789
Amortization of issuance costs on subordinated debt	97	96
Capitalization of mortgage servicing rights	(421)	(1,131)
Net change in fair value of mortgage servicing rights	6,080	(294)
Stock-based compensation expense	4,831	2,820
Provision for credit losses on loans HFI	1,906	1,852
Provision for (reversal of) credit losses on unfunded commitments	386	(1,070)
Provision for mortgage loan repurchases	18	50
Accretion of discounts and premiums on acquired loans, net	(2)	(387)
(Accretion) amortization of premiums and discounts on securities, net	(609)	1,356
(Gain) loss from investment securities, net	(16)	16,213
Originations of loans held for sale	(271,383)	(258,352)
Proceeds from sale of loans held for sale	229,175	251,548
Gain on sale and change in fair value of loans held for sale	(8,418)	(8,279)
Net loss (gain) on write-downs of premises and equipment, other real estate owned and other assets	625	(565)
Provision for deferred income taxes	5,100	207
Equity method investment loss	495	0
Earnings on bank-owned life insurance	(446)	(431)
Changes in:
Operating lease assets and liabilities, net	(268)	(207)
Other assets and interest receivable	12,314	(665)
Accrued expenses and other liabilities	(38,706)	1,927
Net cash (used in) provided by operating activities	(16,458)	36,268
Activity in available-for-sale securities:
Sales	0	207,882
Maturities, prepayments and calls	74,860	66,627
Purchases	(103,731)	(281,579)
Net change in loans	(174,919)	117,904
Net sales of FHLB stock	515	242
Purchases of premises and equipment	(1,663)	(1,620)
Proceeds from the sale of premises and equipment	1,831	137
Proceeds from the sale of other real estate owned	2,668	389
Proceeds from the sale of other assets	243	161
Proceeds from bank-owned life insurance	550	0
Net cash (used in) provided by investing activities	(199,646)	110,143
Cash flows from financing activities:
Net decrease in deposits	(8,436)	(47,856)
Net decrease in securities sold under agreements to repurchase and federal funds purchased	(3,712)	(30,535)
Stock-based compensation withholding payments	(1,062)	(626)
Net proceeds from sale of common stock under employee stock purchase program	424	399
Repurchase of common stock	(9,892)	0
Dividends paid on common stock	(8,865)	(7,965)
Dividend equivalent payments made upon vesting of equity compensation	(135)	(30)
Net cash used in financing activities	(31,678)	(86,613)
Net change in cash and cash equivalents	(247,782)	59,798
Cash and cash equivalents at beginning of the period	1,042,488	810,932
Cash and cash equivalents at end of the period	794,706	870,730
Supplemental cash flow information:
Interest paid	77,434	74,943
Taxes (refunded) paid, net	(8,761)	277
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	2,067	753
Transfers from loans to other assets	1,471	1,031
Transfers from loans to loans held for sale	968	167
Transfers from loans held for sale to loans	1,379	40
Loans provided for sales of other assets	675	65
Decrease in rebooked GNMA loans under optional repurchase program	(4,205)	(353)
Dividends declared not paid on restricted stock units and performance stock units	104	87
Right-of-use assets obtained in exchange for operating lease liabilities	$ 301	$ 0