COMPONENTS OF QUARTERLY AND YEAR TO DATE NET PERIODIC BENEFIT COSTS (Tables)

6 Months Ended

Jun. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Components of net periodic benefit costs

The components of net periodic expense for the Corporation’s pension and other benefit plans for the periods indicated are as follows (in thousands):

	Three Months Ended   June 30,						Six Months Ended   June 30,
	2016			2015			2016			2015
Qualified Pension Plan
Service cost, benefits earned during the period	$	298		$	353		$	594		$	707
Interest cost on projected benefit obligation	470			457			940			914
Expected return on plan assets	(756		)	(824		)	(1,511		)	(1,647		)
Amortization of unrecognized transition obligation	—			—			—			—
Amortization of unrecognized prior service cost	2			3			4			5
Amortization of unrecognized net loss	383			369			767			737
Net periodic pension cost	$	397		$	358		$	794		$	716
Supplemental Pension Plan
Service cost, benefits earned during the period	$	10		$	11		$	21		$	22
Interest cost on projected benefit obligation	13			12			26			24
Expected return on plan assets	—			—			—			—
Amortization of unrecognized prior service cost	—			—			—			—
Amortization of unrecognized net loss	7			13			13			26
Net periodic supplemental pension cost	$	30		$	36		$	60		$	72
Postretirement Plan, Medical and Life
Service cost, benefits earned during the period	$	12		$	12		$	24		$	24
Interest cost on projected benefit obligation	18			16			35			32
Expected return on plan assets	—			—			—			—
Amortization of unrecognized prior service cost	(25		)	(24		)	(49		)	(48		)
Amortization of unrecognized net loss	6			2			12			4
Net periodic postretirement, medical and life cost	$	11		$	6		$	22		$	12