Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net income attributable to FB Financial Corporation and noncontrolling interest	$ 31,831	$ 45,290	$ 86,420	$ 141,466
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization of fixed assets and software			6,105	6,288
Amortization of core deposit and other intangibles			3,546	4,178
Capitalization of mortgage servicing rights			(19,523)	(31,382)
Net change in fair value of mortgage servicing rights	(8,296)	239	(36,392)	788
Stock-based compensation expense			8,153	8,065
Provision for credit losses	8,189	(2,832)	10,241	(27,349)
Provision for credit losses on unfunded commitments	3,178	301	9,197	(2,875)
Provision for mortgage loan repurchases	(800)	0	(1,989)	(266)
Amortization of premiums and accretion of discounts on acquired loans, net			1,339	127
Amortization of premiums and accretion of discounts on securities, net			5,178	6,521
Loss (gain) from securities, net	140	(51)	401	(278)
Originations of loans held for sale			(2,129,129)	(4,926,390)
Repurchases of loans held for sale			(194)	(384)
Proceeds from sale of loans held for sale			2,796,313	4,939,323
Gain on sale and change in fair value of loans held for sale			(43,648)	(126,983)
Net loss (gain) or write-downs of other real estate owned	(435)	(2,005)	89	(2,478)
Gain on other assets	6	(177)	(76)	(162)
Provision for deferred income taxes	3,418	7,366	15,879	20,904
Earnings on bank-owned life insurance			(1,099)	(1,156)
Changes in:
Operating leases			4,485	(781)
Other assets and interest receivable			(23,220)	(1,352)
Accrued expenses and other liabilities			51,583	(46,867)
Net cash provided by (used in) operating activities			743,659	(41,043)
Activity in available-for-sale securities:
Sales			1,218	8,855
Maturities, prepayments and calls	44,352	68,126	170,701	216,032
Purchases			(242,639)	(645,658)
Net change in loans			(1,523,815)	(177,953)
Net change in commercial loans held for sale			43,006	116,158
Sales of FHLB stock			0	4,294
Purchases of FHLB stock			(26,370)	(663)
Purchases of premises and equipment			(6,060)	(5,193)
Proceeds from the sale of premises and equipment			875	0
Proceeds from the sale of other real estate owned	4,335	4,173	4,753	8,834
Proceeds from the sale of other assets			4	0
Net cash used in investing activities			(1,578,327)	(475,294)
Cash flows from financing activities:
Net (decrease) increase in demand deposits			(852,629)	863,646
Net increase (decrease) in time deposits			31,989	(249,765)
Net (decrease) increase in securities sold under agreements to repurchase			(11,708)	9,531
Net increase in short-term FHLB advances			540,000	0
Payments on subordinated debt			0	(60,000)
Amortization of issuance costs and (accretion) of subordinated debt fair value premium, net			291	(79)
Payments on other borrowings			0	(15,000)
Share based compensation withholding payments			(2,635)	(10,042)
Net proceeds from sale of common stock under employee stock purchase program			1,212	1,480
Repurchase of common stock			(32,743)	(436)
Dividends paid on common stock			(18,401)	(15,617)
Dividend equivalent payments made upon vesting of equity compensation			(150)	(707)
Noncontrolling interest distribution			(8)	(8)
Net cash (used in) provided by financing activities			(344,782)	523,003
Net change in cash and cash equivalents			(1,179,450)	6,666
Cash and cash equivalents at beginning of the period			1,797,740	1,317,898
Cash and cash equivalents at end of the period	618,290	1,324,564	618,290	1,324,564
Supplemental cash flow information:
Interest paid			31,322	34,542
Taxes paid			808	55,609
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	421	349	984	4,945
Loans provided for sales of other real estate owned	0	152	0	685
Transfers from loans to loans held for sale			42,997	10,408
Transfers from loans held for sale to loans			23,183	52,151
Rebooked GNMA loans under optional repurchase program			26,485	0
Trade date payable - securities			0	5,996
Dividends declared not paid on restricted stock units	$ 173	$ 340	173	340
Right-of-use assets obtained in exchange for operating lease liabilities			$ 24,605	$ 839