Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2017

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 months ended March 31, 2017 and 2016 are as follows (in thousands):

	Three Months Ended March 31, 2017						Three Months Ended March 31, 2016
	Qualified Pension Plans			Post- employment Benefit Plans			Qualified Pension Plans			Post- employment Benefit Plans
Service cost	$	1,787		$	31		$	1,593		$	41
Interest cost	3,946			959			3,821			1,008
Expected return on plan assets	(4,178		)	—			(3,834		)	—
Amortization of actuarial loss	1,190			271			1,349			31,704
Amortization of prior service cost	(761		)	(455		)	(761		)	(88,017		)
Plan settlement	441			—			—			—
Net periodic benefit cost	2,425			806			2,168			(55,264		)
Less capitalized portion	(134		)	—			(132		)	—
Other post-employment benefit and pension expense/(benefit)	$	2,291		$	806		$	2,036		$	(55,264	)