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

9 Months Ended

Sep. 30, 2017

Retirement Benefits [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   September 30,						Nine Months Ended   September 30,
	2017			2016			2017			2016
Qualified Pension Plan
Service cost, benefits earned during the period	$	—		$	298		$	—		$	892
Interest cost on projected benefit obligation	403			470			1,209			1,410
Expected return on plan assets	(785		)	(756		)	(2,355		)	(2,267		)
Amortization of unrecognized transition obligation	—			—			—			—
Amortization of unrecognized prior service cost	—			1			—			5
Amortization of unrecognized net loss	58			383			174			1,150
Net periodic pension cost (benefit)	$	(324	)	$	396		$	(972	)	$	1,190
Supplemental Pension Plan
Service cost, benefits earned during the period	$	—		$	11		$	—		$	32
Interest cost on projected benefit obligation	12			13			36			39
Expected return on plan assets	—			—			—			—
Amortization of unrecognized prior service cost	—			—			—			—
Amortization of unrecognized net loss	1			6			3			19
Net periodic supplemental pension cost	$	13		$	30		$	39		$	90
Postretirement Plan, Medical and Life
Service cost, benefits earned during the period	$	—		$	11		$	—		$	35
Interest cost on projected benefit obligation	3			18			11			53
Expected return on plan assets	—			—			—			—
Amortization of unrecognized prior service cost	(55		)	(23		)	(165		)	(72		)
Amortization of unrecognized net loss	29			7			87			19
Net periodic postretirement, medical and life cost (benefit)	$	(23	)	$	13		$	(67	)	$	35