Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net income attributable to FB Financial Corporation and noncontrolling interest	$ 35,236	$ 52,874
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization of fixed assets and software	2,036	2,056
Amortization of core deposit and other intangibles	1,244	1,440
Capitalization of mortgage servicing rights	(9,812)	(11,594)
Net change in fair value of mortgage servicing rights	(19,351)	(12,601)
Stock-based compensation expense	2,582	2,666
Provision for credit losses	(6,129)	(11,632)
Provision for credit losses on unfunded commitments	1,882	(2,222)
Provision for mortgage loan repurchases	(389)	440
Amortization of premiums and accretion of discounts on acquired loans, net	2,352	58
Amortization of premiums and accretion of discounts on securities, net	1,992	2,150
Loss (gain) from securities, net	152	(83)
Originations of loans held for sale	(993,733)	(1,757,932)
Proceeds from sale of loans held for sale	1,330,701	1,648,695
Gain on sale and change in fair value of loans held for sale	(21,675)	(52,811)
Net loss (gain) or write-downs of other real estate owned	498	(496)
(Gain) loss on other assets	(64)	11
Provision for deferred income taxes	9,313	9,639
Earnings on bank-owned life insurance	(354)	(402)
Changes in:
Operating leases	(190)	129
Other assets and interest receivable	(62,043)	(907)
Accrued expenses and other liabilities	13,900	(41,660)
Net cash provided by (used in) operating activities	288,148	(172,182)
Activity in available-for-sale securities:
Maturities, prepayments and calls	57,443	61,040
Purchases	(170,093)	(131,268)
Net change in loans	(363,354)	45,584
Net change in commercial loans held for sale	946	39,566
Purchases of FHLB stock	(2,216)	(525)
Purchases of premises and equipment	(601)	(2,050)
Proceeds from the sale of other real estate owned	121	2,495
Net cash (used in) provided by investing activities	(477,754)	14,842
Cash flows from financing activities:
Net increase in demand deposits	238,893	855,673
Net decrease in time deposits	(75,765)	(56,824)
Net decrease in securities sold under agreements to repurchase	(14,779)	(2,965)
Payments on subordinated debt	0	(40,000)
Accretion of subordinated debt fair value premium and amortization of issuance costs, net	97	(158)
Payments on other borrowings	0	(15,000)
Share based compensation withholding payments	(1,488)	(1,715)
Net proceeds from sale of common stock under employee stock purchase program	687	833
Repurchase of common stock	(6,203)	0
Dividends paid	(6,265)	(5,269)
Net cash provided by financing activities	135,177	734,575
Net change in cash and cash equivalents	(54,429)	577,235
Cash and cash equivalents at beginning of the period	1,797,740	1,317,898
Cash and cash equivalents at end of the period	1,743,311	1,895,133
Supplemental cash flow information:
Interest paid	8,631	14,794
Taxes paid	72	15,117
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	563	1,395
Loans provided for sales of other real estate owned	0	330
Transfers from loans to loans held for sale	8,700	2,521
Transfers from loans held for sale to loans	47,956	14,413
Dividends declared not paid on restricted stock units	60	38
Right-of-use assets obtained in exchange for operating lease liabilities	$ 283	$ 157