Pension Benefits (Tables)

9 Months Ended

Sep. 30, 2017

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Components of the net periodic benefit cost for the Pension Plans [Table Text Block]

The following table presents the components of the net periodic benefit cost for the Pension Plans:

	For the Three Months Ended   September 30,						For the Nine Months Ended   September 30,
	2017			2016			2017			2016
	(in thousands)
Service cost	$	1,660		$	2,050		$	4,979		$	6,150
Interest cost	673			727			2,017			2,181
Expected return on plan assets that reduces periodic pension benefit cost	(561		)	(559		)	(1,683		)	(1,677		)
Amortization of prior service cost	4			4			13			13
Amortization of net actuarial loss	324			396			973			1,187
Net periodic benefit cost	$	2,100		$	2,618		$	6,299		$	7,854