Pension Plan and Postretirement Benefits Other Than Pension (Tables)

9 Months Ended

Sep. 30, 2018

Pension Plan and Postretirement Benefits Other Than Pension

Schedule of components of net periodic pension and other postretirement costs

				Other						Other
	Pension Benefits			Postretirement Benefits			Pension Benefits			Postretirement Benefits
	Three months ended September 30,				Three months ended September 30,		Nine months ended September 30,				Nine months ended September 30,
	2018		2017		2018	2017	2018		2017		2018	2017
		(in thousands)						(in thousands)
Components of net periodic benefit cost:
Service cost	$	—	2,958	$	—	—	$	—	8,367	$	—	—
Interest cost		1,497	1,522		14	15		4,490	4,780		41	44
Expected return on plan assets		(2,065)	(2,510)		—	—		(6,196)	(7,627)		—	—
Actuarial loss		—	6,552		—	—		—	6,552		—	—
Actuarial gain amortization		—	—		(30)	(45)		—	—		(90)	(135)
Prior service credit amortization		—	—		(1)	(1)		—	—		(2)	(3)
Curtailment gain		—	(31,621)		—	—			(31,621)		—	—
Total	$	(568)	(23,099)	$	(17)	(31)	$	(1,706)	(19,549)	$	(51)	(94)