Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2017

Retirement Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

The net periodic benefit cost recognized for the three, six and twelve months endedJune 30, 2017 and 2016 is made up of the components listed below as determined using the projected unit credit actuarial cost method (in thousands):

	Three Months Ended						Six Months Ended						Twelve Months Ended
	June 30,						June 30,						June 30,
	2017			2016			2017			2016			2017			2016
Components of net periodic benefit cost:
Service cost	$	1,989		$	1,905		$	4,259		$	3,810		$	8,450		$	8,402
Interest cost	3,282			3,265			6,530			6,530			13,039			13,775
Expected return on plan assets	(4,787		)	(4,713		)	(9,595		)	(9,425		)	(19,049		)	(19,325		)
Amortization of:
Net loss	2,138			1,887			4,227			3,775			7,791			8,922
Prior service benefit	(875		)	(877		)	(1,753		)	(1,755		)	(3,504		)	(3,486		)
Net periodic benefit cost	$	1,747		$	1,467		$	3,668		$	2,935		$	6,727		$	8,288

Other Postretirement Benefit Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

The net periodic benefit recognized for the three, six and twelve months endedJune 30, 2017 and 2016 is made up of the components listed below (in thousands):

	Three Months Ended						Six Months Ended						Twelve Months Ended
	June 30,						June 30,						June 30,
	2017			2016			2017			2016			2017			2016
Components of net periodic benefit:
Service cost	$	530		$	715		$	1,118		$	1,430		$	2,457		$	3,134
Interest cost	684			872			1,362			1,745			2,784			3,730
Expected return on plan assets	(483		)	(460		)	(953		)	(920		)	(1,868		)	(1,940		)
Amortization of:
Prior service benefit	(1,538		)	(787		)	(3,076		)	(1,575		)	(5,402		)	(3,093		)
Net gain	(444		)	(665		)	(839		)	(1,330		)	(1,883		)	(2,355		)
Net periodic benefit	$	(1,251	)	$	(325	)	$	(2,388	)	$	(650	)	$	(3,912	)	$	(524	)