Pension and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 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 June 30,						Six months ended June 30,
Pensions	2015			2014			2015			2014
Service cost	$	1,299		$	1,052		$	2,752		$	2,307
Interest cost	5,297			5,540			9,992			10,978
Expected return on plan assets	(8,589		)	(8,483		)	(16,159		)	(17,053		)
Amortization of prior service cost	77			157			155			334
Amortization of actuarial losses	4,056			2,270			7,485			4,232
Curtailment loss	—			—			—			219
Settlement loss	—			582			—			582
Special termination benefits	—			—			—			715
Net periodic benefit cost	$	2,140		$	1,118		$	4,225		$	2,314

	Three months ended June 30,						Six months ended June 30,
Other Postretirement Benefits	2015			2014			2015			2014
Service cost	$	36		$	29		$	73		$	81
Interest cost	425			540			918			1,099
Amortization of prior service credit	(141		)	(218		)	(282		)	(435		)
Amortization of actuarial losses	244			267			505			483
Curtailment loss	—			—			—			4
Net periodic benefit cost	$	564		$	618		$	1,214		$	1,232