Minimum capital requirements (Tables)

6 Months Ended

Jun. 30, 2020

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 presented below at period-end.

	Actual				For capital adequacy  purposes				Minimum Capital adequacy with capital buffer				To be well capitalized under prompt corrective action provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio		Amount		Ratio
June 30, 2020
Total Capital (to risk-weighted assets)
FB Financial Corporation	$	735,555	13.4	%	$	439,137	8.0	%	$	576,368	10.5	%	N/A		N/A
FirstBank	742,321		13.5	%	439,894		8.0	%	577,361		10.5	%	$	549,867	10.0	%
Tier 1 Capital (to risk-weighted assets)
FB Financial Corporation	$	666,090	12.1	%	$	330,293	6.0	%	$	467,914	8.5	%	N/A		N/A
FirstBank	672,856		12.3	%	328,222		6.0	%	464,982		8.5	%	$	437,630	8.0	%
Tier 1 Capital (to average assets)
FB Financial Corporation	$	666,090	9.7	%	$	274,676	4.0	%	N/A		N/A		N/A		N/A
FirstBank	672,856		9.7	%	277,466		4.0	%	N/A		N/A		$	346,833	5.0	%
Common Equity Tier 1 Capital (to risk- weighted assets)
FB Financial Corporation	$	636,090	11.6	%	$	246,759	4.5	%	$	383,847	7.0	%	N/A		N/A
FirstBank	672,856		12.3	%	246,167		4.5	%	382,926		7.0	%	$	355,574	6.5	%

	Actual				For capital adequacy purposes				Minimum Capital adequacy with capital buffer				To be well capitalized under prompt corrective action provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio		Amount		Ratio
December 31, 2019
Total Capital (to risk-weighted assets)
FB Financial Corporation	$	633,549	12.2	%	$	415,442	8.0	%	$	545,268	10.5	%	N/A		N/A
FirstBank	623,432		12.1	%	412,186		8.0	%	540,995		10.5	%	$	515,233	10.0	%
Tier 1 Capital (to risk-weighted assets)
FB Financial Corporation	$	602,410	11.6	%	$	311,591	6.0	%	$	441,421	8.5	%	N/A		N/A
FirstBank	592,293		11.5	%	309,022		6.0	%	437,782		8.5	%	$	412,030	8.0	%
Tier 1 Capital (to average assets)
FB Financial Corporation	$	602,410	10.1	%	$	238,578	4.0	%	N/A		N/A		N/A		N/A
FirstBank	592,293		9.9	%	239,310		4.0	%	N/A		N/A		$	299,138	5.0	%
Common Equity Tier 1 Capital (to risk- weighted assets)
FB Financial Corporation	$	572,410	11.1	%	$	232,058	4.5	%	$	360,979	7.0	%	N/A		N/A
FirstBank	592,293		11.5	%	231,767		4.5	%	360,526		7.0	%	$	334,774	6.5	%