CAPITAL (Tables)

12 Months Ended

Dec. 31, 2021

Banking Regulation, Total Capital [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

	Actual				Minimum capital required - Basel III				PCA requirement to be considered well capitalized
(Dollars in thousands)	Capital amount		Ratio		Capital amount		Ratio		Capital amount		Ratio
December 31, 2021
Common equity tier 1 capital to risk-weighted assets
Consolidated	$	1,262,789	10.84	%	$	815,197	7.00	%	N/A		N/A
First Financial Bank	1,513,175		13.01	%	813,974		7.00	%	$	755,833	6.50	%
Tier 1 capital to risk-weighted assets
Consolidated	1,306,571		11.22	%	989,882		8.50	%	N/A		N/A
First Financial Bank	1,513,708		13.02	%	988,397		8.50	%	930,256		8.00	%
Total capital to risk-weighted assets
Consolidated	1,642,549		14.10	%	1,222,795		10.50	%	N/A		N/A
First Financial Bank	1,589,570		13.67	%	1,220,960		10.50	%	1,162,820		10.00	%
Leverage
Consolidated	1,306,571		8.70	%	600,410		4.00	%	N/A		N/A
First Financial Bank	1,513,708		10.10	%	599,578		4.00	%	749,472		5.00	%

	Actual				Minimum capital required - Basel III				PCA requirement to be considered well capitalized
(Dollars in thousands)	Capital amount		Ratio		Capital amount		Ratio		Capital amount		Ratio
December 31, 2020
Common equity tier 1 capital to risk-weighted assets
Consolidated	$	1,325,922	11.82	%	$	785,338	7.00	%	N/A		N/A
First Financial Bank	1,452,403		12.95	%	784,807		7.00	%	$	728,749	6.50	%
Tier 1 capital to risk-weighted assets
Consolidated	1,368,818		12.20	%	953,625		8.50	%	N/A		N/A
First Financial Bank	1,452,507		12.96	%	952,980		8.50	%	896,922		8.00	%
Total capital to risk-weighted assets
Consolidated	1,744,802		15.55	%	1,178,007		10.50	%	N/A		N/A
First Financial Bank	1,560,457		13.92	%	1,177,211		10.50	%	1,121,153		10.00	%
Leverage
Consolidated	1,368,818		9.55	%	573,526		4.00	%	N/A		N/A
First Financial Bank	1,452,507		10.14	%	573,094		4.00	%	716,367		5.00	%