Pension and Postretirement Benefit Obligations (Tables)

9 Months Ended

Sep. 30, 2018

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Pension Cost

The components of net periodic pension cost were as follows:

	Third Quarter						First Three Quarters
(in thousands)	2018			2017			2018			2017
Service cost	$	1,412		$	150		$	4,237		$	450
Interest cost		2,856			2,978			8,568			8,936
Expected return on plan assets		(3,853	)		(3,399	)		(11,557	)		(10,197	)
Recognized net actuarial loss		934			807			2,800			2,421
Amortization of prior service cost		6			7			18			21
Net periodic pension cost	$	1,355		$	543		$	4,066		$	1,631

Components of Net Periodic Postretirement Benefit Cost

The components of net periodic postretirement benefit cost were as follows:

	Third Quarter						First Three Quarters
(in thousands)	2018			2017			2018			2017
Service cost	$	502		$	572		$	1,507		$	1,716
Interest cost		696			910			2,088			2,732
Recognized net actuarial loss		499			648			1,497			1,944
Amortization of prior service cost		(462	)		(745	)		(1,386	)		(2,237	)
Net periodic postretirement benefit cost	$	1,235		$	1,385		$	3,706		$	4,155