PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Tables)

6 Months Ended

Jun. 30, 2018

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS

Summary of the components of net periodic benefit cost

	Three Months Ended June 30
	Nonunion Defined				Supplemental				Postretirement
	Benefit Pension Plan				Benefit Plan				Health Benefit Plan
	2018		2017		2018		2017		2018		2017
	(in thousands)
Service cost	$	—	$	—	$	—	$	—	$	91	$	122
Interest cost		1,108		1,149		27		25		210		265
Expected return on plan assets		(378)		(2,054)		—		—		—		—
Amortization of prior service credit		—		—		—		—		(24)		(48)
Pension settlement expense		431		744		—		—		—		—
Amortization of net actuarial loss(1)		592		757		20		21		76		174
Net periodic benefit cost	$	1,753	$	596	$	47	$	46	$	353	$	513

	Six Months Ended June 30
	Nonunion Defined				Supplemental				Postretirement
	Benefit Pension Plan				Benefit Plan				Health Benefit Plan
	2018		2017		2018		2017		2018		2017
	(in thousands)
Service cost	$	—	$	—	$	—	$	—	$	183	$	244
Interest cost		2,123		2,389		54		51		419		530
Expected return on plan assets		(779)		(4,221)		—		—		—		—
Amortization of prior service credit		—		—		—		—		(47)		(95)
Pension settlement expense		1,085		2,701		—		—		—		—
Amortization of net actuarial loss(1)		1,370		1,643		40		41		152		347
Net periodic benefit cost	$	3,799	$	2,512	$	94	$	92	$	707	$	1,026

⁽¹⁾ The Company amortizes actuarial losses over the average remaining active service period of the plan participants and does not use a corridor approach.

Schedule of changes in the projected benefit obligation and plan assets of the nonunion defined benefit pension plan

	Nonunion Defined
	Benefit Pension Plan
	(in thousands)
Change in benefit obligations
Benefit obligations at December 31, 2017	$	137,417
Interest cost		2,123
Actuarial gain(1)		(4,924)
Benefits paid		(8,578)
Benefit obligations at June 30, 2018		126,038
Change in plan assets
Fair value of plan assets at December 31, 2017		124,831
Actual return on plan assets		1,093
Benefits paid		(8,578)
Fair value of plan assets at June 30, 2018		117,346
Funded status at period end(2)	$	(8,692)
Accumulated benefit obligation	$	126,038

⁽¹⁾ Primarily related to the impact of an increase in the discount rate at the June 30, 2018 remeasurement upon settlement compared to the discount rate at the December 31, 2017 measurement date.

⁽²⁾ Noncurrent liability recognized within pension and postretirement liabilities in the accompanying consolidated balance sheet at June 30, 2018.