EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Amounts Recognized in Balance Sheet and Income Statement [Table Text Block]

The following tables set forth information concerning amounts recognized in First Financial's Consolidated Balance Sheets and Consolidated Statements of Income related to the Company's pension plan:

	December 31,
(Dollars in thousands)	2016			2015
Change in benefit obligation
Benefit obligation at beginning of year	$	60,664		$	59,780
Service cost	5,034			4,807
Interest cost	2,262			2,120
Actuarial gain (loss)	142			(1,017		)
Benefits paid, excluding settlement	(5,373		)	(5,026		)
Benefit obligation at end of year	62,729			60,664
Change in plan assets
Fair value of plan assets at beginning of year	125,714			133,326
Actual return on plan assets	10,670			(2,586		)
Benefits paid, excluding settlement	(5,373		)	(5,026		)
Fair value of plan assets at end of year	131,011			125,714
Amounts recognized in the Consolidated Balance Sheets
Assets	68,282			65,050
Liabilities	0			0
Net amount recognized	$	68,282		$	65,050
Amounts recognized in accumulated other comprehensive income (loss)
Net actuarial loss	$	38,278		$	40,770
Net prior service cost	(2,334		)	(2,747		)
Deferred tax assets	(13,141		)	(13,975		)
Net amount recognized	$	22,803		$	24,048
Change in accumulated other comprehensive income (loss)	$	(1,245	)	$	6,144
Accumulated benefit obligation	$	61,909		$	60,040

Schedule of Components of Net Periodic Benefit Cost [Table Text Block]

Components of net periodic benefit cost
	December 31,
(Dollars in thousands)	2016			2015			2014
Service cost	$	5,034		$	4,807		$	4,119
Interest cost	2,262			2,120			2,388
Expected return on assets	(9,644		)	(9,444		)	(9,055		)
Amortization of prior service cost	(413		)	(413		)	(413		)
Recognized net actuarial loss	1,608			1,888			1,824
Net periodic benefit (income) cost	(1,153		)	(1,042		)	(1,137		)
Other changes recognized in accumulated other comprehensive income (loss)
Net actuarial (gain) loss	(884		)	11,014			5,058
Prior service cost	0			0			0
Amortization of prior service cost	413			413			413
Amortization of gain	(1,608		)	(1,888		)	(1,824		)
Total recognized in accumulated other comprehensive income (loss)	(2,079		)	9,539			3,647
Total recognized in net periodic benefit cost and accumulated other comprehensive income (loss)	$	(3,232	)	$	8,497		$	2,510
Amount expected to be recognized in net periodic pension expense in the coming year
Amortization of (gain) loss	$	1,754		$	1,642		$	1,780
Amortization of prior service credit	(413		)	(413		)	(413		)

Schedule of Assumptions Used [Table Text Block]

Assumptions
	December 31,
	2016		2015		2014
Benefit obligations
Discount rate	3.88	%	4.05	%	3.76	%
Rate of compensation increase	3.50	%	3.50	%	3.50	%
Net periodic benefit cost
Discount rate	4.05	%	3.76	%	4.62	%
Expected return on plan assets	7.50	%	7.50	%	7.50	%
Rate of compensation increase	3.50	%	3.50	%	3.50	%

Schedule of Changes in Fair Value of Plan Assets [Table Text Block]

The fair value of the plan assets as of December 31, 2016 by asset category is shown in the table that follows:

	Fair Value Measurements
(Dollars in thousands)	Total		Quoted Prices in  Active Markets  for  Identical Assets  (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Asset Category
Cash	$	190	$	190	$	0	$	0
U. S. Government agencies	6,026		0		6,026		0
Fixed income mutual funds	66,483		66,483		0		0
Equity mutual funds	58,311		58,311		0		0
Total	$	131,010	$	124,984	$	6,026	$	0

The fair value of the plan assets as of December 31, 2015 by asset category is shown in the table that follows:

	Fair Value Measurements
(Dollars in thousands)	Total		Quoted Prices in  Active Markets  for  Identical Assets  (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Asset Category
Cash	$	181	$	181	$	0	$	0
U. S. Government agencies	6,573		6,573		0		0
Fixed income mutual funds	63,885		63,885		0		0
Equity mutual funds	55,075		55,075		0		0
Total	$	125,714	$	125,714	$	0	$	0

Schedule of Expected Benefit Payments [Table Text Block]

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid:

(Dollars in thousands)	Retirement Benefits
2017	$	4,081
2018	4,421
2019	4,143
2020	5,127
2021	5,660
Thereafter	27,515