Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net income attributable to FB Financial Corporation and noncontrolling interest	$ 19,353	$ 43,302	$ 54,589	$ 96,176
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization of fixed assets and software			4,048	4,148
Amortization of core deposit and other intangibles			2,438	2,834
Capitalization of mortgage servicing rights			(15,070)	(22,167)
Net change in fair value of mortgage servicing rights	(8,745)	13,150	(28,096)	549
Stock-based compensation expense			5,620	5,181
Provision for credit losses	8,181	(12,885)	2,052	(24,517)
Provision for credit losses on unfunded commitments	4,137	(954)	6,019	(3,176)
Provision for mortgage loan repurchases	(800)	(706)	(1,189)	(266)
Amortization of premiums and accretion of discounts on acquired loans, net			2,288	284
Amortization of premiums and accretion of discounts on securities, net			3,692	4,390
Loss (gain) from securities, net	109	(144)	261	(227)
Originations of loans held for sale			(1,719,488)	(3,308,882)
Proceeds from sale of loans held for sale			2,213,443	3,355,152
Gain on sale and change in fair value of loans held for sale			(35,410)	(86,031)
Net loss (gain) or write-downs of other real estate owned	26	23	524	(473)
(Gain) loss on other assets	(18)	4	(82)	15
Provision for deferred income taxes	3,148	3,899	12,461	13,538
Earnings on bank-owned life insurance			(728)	(792)
Changes in:
Operating leases			166	(677)
Other assets and interest receivable			13,566	(17,810)
Accrued expenses and other liabilities			7,279	(92,355)
Net cash provided by (used in) operating activities			528,383	(75,106)
Activity in available-for-sale securities:
Sales			1,218	0
Maturities, prepayments and calls	126,349	86,866	126,349	147,906
Purchases			(243,209)	(354,762)
Net change in loans			(1,029,702)	(95,938)
Net change in commercial loans held for sale			39,300	91,792
Sales of FHLB stock			0	2,346
Purchases of FHLB stock			(2,364)	(525)
Purchases of premises and equipment			(3,224)	(1,168)
Proceeds from the sale of premises and equipment			875	0
Proceeds from the sale of other real estate owned	297	2,166	418	4,661
Net cash used in investing activities			(1,110,339)	(205,688)
Cash flows from financing activities:
Net (decrease) increase in demand deposits			(334,155)	900,733
Net increase (decrease) in time deposits			46,677	(154,814)
Net (decrease) increase in securities sold under agreements to repurchase			(9,010)	857
Payments on subordinated debt			0	(40,000)
Amortization of issuance costs and (accretion) of subordinated debt fair value premium, net			193	(176)
Payments on other borrowings			0	(15,000)
Share based compensation withholding payments			(2,146)	(1,940)
Net proceeds from sale of common stock under employee stock purchase program			687	833
Repurchase of common stock			(32,743)	0
Dividends paid			(12,418)	(10,492)
Noncontrolling interest distribution			(8)	(8)
Net cash (used in) provided by financing activities			(342,923)	679,993
Net change in cash and cash equivalents			(924,879)	399,199
Cash and cash equivalents at beginning of the period			1,797,740	1,317,898
Cash and cash equivalents at end of the period	872,861	1,717,097	872,861	1,717,097
Supplemental cash flow information:
Interest paid			15,638	24,611
Taxes paid			726	45,335
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	0	3,201	563	4,596
Loans provided for sales of other real estate owned	0	203	0	533
Transfers from loans to loans held for sale			20,016	3,709
Transfers from loans held for sale to loans			14,179	29,322
Trade date payable - securities			0	41,722
Dividends declared not paid on restricted stock units	$ 118	$ 128	118	128
Right-of-use assets obtained in exchange for operating lease liabilities			$ 2,317	$ 670