REGULATORY MATTERS: (Tables)

12 Months Ended

Dec. 31, 2016

Banking and Thrift [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations

The following table presents the actual and required capital amounts and related ratios for the Corporation and First Financial Bank, N.A., at year-end 2016 and 2015. 

									To Be Well Capitalized
					For Capital				Under Prompt Corrective
	Actual				Adequacy Purposes				Action Provisions
(Dollar amounts in thousands)	Amount		Ratio		Amount		Ratio		Amount	Ratio
Total risk-based capital
Corporation – 2016	$	411,713	18.26	%	$	194,435	8.625	%	N/A	N/A
Corporation – 2015	$	398,903	18.62	%	$	171,346	8.00	%	N/A	N/A
First Financial Bank – 2016	384,522		17.64	%	188,003		8.625	%	217,974	10.00	%
First Financial Bank – 2015	372,922		18.05	%	165,261		8.00	%	206,576	10.00	%
Common equity tier I capital
Corporation – 2016	$	392,939	17.43	%	$	115,534	5.125	%	N/A	N/A
Corporation – 2015	$	378,957	17.69	%	$	96,382	4.50	%	N/A	N/A
First Financial Bank – 2016	368,797		16.92	%	111,712		5.125	%	141,683	6.50	%
First Financial Bank – 2015	355,853		17.23	%	92,959		4.50	%	134,274	6.50	%
Tier I risk-based capital
Corporation – 2016	$	392,939	17.43	%	$	149,348	6.625	%	N/A	N/A
Corporation – 2015	$	378,957	17.69	%	$	128,509	6.00	%	N/A	N/A
First Financial Bank – 2016	368,797		16.92	%	144,408		6.625	%	174,379	8.00	%
First Financial Bank – 2015	355,853		17.23	%	123,945		6.00	%	165,261	8.00	%
Tier I leverage capital
Corporation – 2016	$	392,939	13.39	%	$	117,376	4.00	%	N/A	N/A
Corporation – 2015	$	378,957	12.92	%	$	117,352	4.00	%	N/A	N/A
First Financial Bank – 2016	368,797		12.82	%	115,047		4.00	%	143,809	5.00	%
First Financial Bank – 2015	355,853		12.50	%	113,888		4.00	%	142,360	5.00	%