Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Periodic Benefit Costs of Pension and Post-Retirement Healthcare

Components of the net periodic benefit cost related to the Company's qualified pension plans and other post-employment benefit plans for the three and nine months ended September 30, 2016 and 2015 are as follows (in thousands):

	Three Months Ended September 30, 2016						Three Months Ended September 30, 2015
	Qualified Pension Plans			Post- employment Benefit Plans			Qualified Pension Plans			Post- employment Benefit Plans
Service cost	$	1,847		$	9		$	1,653		$	62
Interest cost	3,719			929			3,702			1,005
Expected return on plan assets	(3,848		)	—			(3,688		)	—
Amortization of actuarial loss	1,343			18,118			1,570			32,775
Amortization of prior service cost	(760		)	(89,101		)	(863		)	(89,550		)
Plan curtailment	—			—			(4,207		)	—
Plan settlement	477			—			110			—
Net periodic benefit cost	2,778			(70,045		)	(1,723		)	(55,708		)
Less capitalized portion	(161		)	—			(137		)	—
Other post-employment benefit and pension expense	$	2,617		$	(70,045	)	$	(1,860	)	$	(55,708	)

	Nine Months Ended September 30, 2016						Nine Months Ended September 30, 2015
	Qualified Pension Plans			Post- employment Benefit Plans			Qualified Pension Plans			Post- employment Benefit Plans
Service cost	$	5,033		$	91		$	6,822		$	4,479
Interest cost	11,360			2,945			11,146			6,683
Expected return on plan assets	(11,516		)	—			(10,911		)	—
Amortization of actuarial loss	4,040			81,526			5,311			80,649
Amortization of prior service cost	(2,281		)	(265,377		)	(2,070		)	(215,076		)
Plan curtailment	—			—			(4,207		)	—
Plan settlement	477			—			717			—
Net periodic benefit cost	7,113			(180,815		)	6,808			(123,265		)
Less capitalized portion	(440		)	—			(469		)	—
Other post-employment benefit and pension expense	$	6,673		$	(180,815	)	$	6,339		$	(123,265	)