Pension and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs

Pension and other postretirement benefits expenses consisted of the following:

	Three months ended September 30,						Nine months ended September 30,
Pensions	2015			2014			2015			2014
Service cost	$	1,374		$	1,132		$	4,126		$	3,439
Interest cost	4,976			5,455			14,968			16,432
Expected return on plan assets	(8,048		)	(8,476		)	(24,207		)	(25,529		)
Amortization of prior service cost	76			152			231			486
Amortization of actuarial losses	3,730			2,141			11,215			6,374
Curtailment loss	—			—			—			219
Settlement loss	—			281			—			863
Special termination benefits	—			—			—			715
Net periodic benefit cost	$	2,108		$	685		$	6,333		$	2,999

	Three months ended September 30,						Nine months ended September 30,
Other Postretirement Benefits	2015			2014			2015			2014
Service cost	$	36		$	29		$	109		$	110
Interest cost	459			540			1,377			1,638
Amortization of prior service credit	(141		)	(218		)	(423		)	(653		)
Amortization of actuarial losses	253			268			758			751
Curtailment loss	—			—			—			4
Net periodic benefit cost	$	607		$	619		$	1,821		$	1,850