Minimum capital requirements (Tables)

12 Months Ended

Dec. 31, 2021

Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]

Schedule of Actual and Required Capital Amounts and Ratios

Actual and required capital amounts and ratios are included below as of the dates indicated.

	Actual				Minimum Capital adequacy with capital buffer				To be well capitalized under prompt corrective action provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio
December 31, 2021
Total Capital (to risk-weighted assets)
FB Financial Corporation	$	1,434,581	14.5	%	$	1,039,984	10.5	%	N/A		N/A
FirstBank	1,396,407		14.1	%	1,038,760		10.5	%	$	989,295	10.0	%
Tier 1 Capital (to risk-weighted assets)
FB Financial Corporation	$	1,251,874	12.6	%	$	841,892	8.5	%	N/A		N/A
FirstBank	1,213,700		12.3	%	840,901		8.5	%	$	791,436	8.0	%
Tier 1 Capital (to average assets)
FB Financial Corporation	$	1,251,874	10.5	%	$	474,831	4.0	%	N/A		N/A
FirstBank	1,213,700		10.2	%	474,044		4.0	%	$	592,555	5.0	%
Common Equity Tier 1 Capital (to risk-weighted assets)
FB Financial Corporation	$	1,221,874	12.3	%	$	693,322	7.0	%	N/A		N/A
FirstBank	1,213,700		12.3	%	692,507		7.0	%	$	643,042	6.5	%

	Actual				Minimum Capital adequacy with capital buffer				To be well capitalized under prompt corrective action provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio
December 31, 2020
Total Capital (to risk-weighted assets)
FB Financial Corporation	$	1,358,897	15.0	%	$	952,736	10.5	%	N/A		N/A
FirstBank	1,353,279		14.9	%	951,327		10.5	%	$	906,026	10.0	%
Tier 1 Capital (to risk-weighted assets)
FB Financial Corporation	$	1,090,364	12.0	%	$	771,262	8.5	%	N/A		N/A
FirstBank	1,142,548		12.6	%	770,122		8.5	%	$	724,820	8.0	%
Tier 1 Capital (to average assets)
FB Financial Corporation	$	1,090,364	10.0	%	$	435,064	4.0	%	N/A		N/A
FirstBank	1,142,548		10.5	%	435,279		4.0	%	$	544,098	5.0	%
Common Equity Tier 1 Capital (to risk-weighted assets)
FB Financial Corporation	$	1,060,364	11.7	%	$	635,157	7.0	%	N/A		N/A
FirstBank	1,142,548		12.6	%	634,218		7.0	%	$	588,917	6.5	%