Pension Benefits (Tables)

6 Months Ended

Jun. 30, 2020

Defined Benefit Plan [Abstract]

Components of the net periodic benefit cost for the pension plans [Table Text Block]

Components of Net Periodic Benefit Cost for the Pension Plans

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2020		2019		2020		2019
	(in thousands)
Components of net periodic benefit cost:
Service cost	$	863	$	1,108	$	2,258	$	2,791
Interest cost	480		739		1,178		1,395
Expected return on plan assets that reduces periodic pension benefit cost	(474)		(321)		(867)		(787)
Amortization of prior service cost	5		5		9		9
Amortization of net actuarial loss	235		147		475		479
Net periodic benefit cost	$	1,109	$	1,678	$	3,053	$	3,887