Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 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 March 31,
Components of Net Period Benefit Cost	2020			2019
	(in thousands)
Service cost	$	2,667		$	2,096
Other cost:
Interest cost	4,970			5,608
Expected return on plan assets	(6,286		)	(5,483		)
Recognized net actuarial loss	978			887
Total other components of the net periodic benefit cost	(338		)	1,012
Net periodic benefit cost	$	2,329		$	3,108