Pension Benefits (Tables)

9 Months Ended

Sep. 30, 2018

Defined Benefit Plan [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,
	2018			2017			2018			2017
	(in thousands)
Service cost	$	1,683		$	1,660		$	5,048		$	4,979
Interest cost	657			673			1,967			2,017
Expected return on plan assets that reduces periodic pension benefit cost	(466		)	(561		)	(1,397		)	(1,683		)
Amortization of prior service cost	4			4			13			13
Amortization of net actuarial loss	331			324			995			973
Net periodic benefit cost	$	2,209		$	2,100		$	6,626		$	6,299