Pension and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Summary of Net Periodic Pension and Other Postemployment Benefit Costs

Net periodic pension cost recognized during the periods included the following components (in thousands):

	Three months ended March 31,
	2016			2015
Service cost	$	3,781		$	4,189
Interest cost	6,502			7,860
Expected return on plan assets	(9,915		)	(10,414		)
Amortization of net loss	5,108			6,311
Amortization of prior service credit	(1,245		)	(1,115		)
Total net pension cost	$	4,231		$	6,831

Other postretirement benefit cost recognized during the periods included the following components (in thousands):

	Three months ended March 31,
	2016			2015
Service cost	$	114		$	320
Interest cost	509			695
Amortization of net loss	(1		)	(2		)
Amortization of prior service credit	(96		)	—
Total other postretirement benefit cost	$	526		$	1,013