Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2020

Retirement Benefits [Abstract]

Schedule of net periodic benefit cost

The components of net periodic benefit cost for the Company’s defined benefit and other post-retirement plans included the following: 

	Three months ended September 30,				Nine months ended September 30,
Components of Net Period Benefit Cost	2020		2019		2020		2019
	(in thousands)
Service cost	$	2,695	$	2,120	$	8,029	$	6,311
Other cost:
Interest cost	4,970		5,584		14,910		16,799
Expected return on plan assets	(6,293)		(5,487)		(18,865)		(16,452)
Recognized net actuarial loss	1,460		824		3,416		2,599
Total other components of the net periodic benefit cost	137		921		(539)		2,946
Curtailment loss	1,753		—		1,753		—
Special termination benefits	5,258		—		5,258		—
Net periodic benefit cost	$	9,843	$	3,041	$	14,501	$	9,257