Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Summary of components of net pension expense

The components of net pension expense for the plans for the periods indicated are as follows:

	For the Three Months Ended March 31,
	2021		2020
	(In Thousands)
Components of net periodic benefit cost:
Service cost	$	7,896	$	6,232
Interest cost	1,269		2,616
Expected return on plan assets	(8,141)		(7,425)
Prior service (credit) cost	(2,946)		6
Recognized net actuarial loss	3,538		2,361
Net periodic benefit cost	$	1,616	$	3,790

Schedule of Assets Held in Rabbi Trust

The following table presents the book value, mark-to-market, and fair value of assets held in rabbi trust accounts by asset type:

	As of March 31, 2021						As of December 31, 2020
	Book Value		Mark-to-Market		Fair Value		Book Value		Mark-to-Market		Fair Value
Asset Type	(In thousands)
Cash and cash equivalents	$	5,230	$	—	$	5,230	$	5,157	$	—	$	5,157
Equities	61,662		18,828		80,490		59,235		19,492		78,727
Fixed income	8,110		175		8,285		7,441		358		7,799
Total assets	$	75,002	$	19,003	$	94,005	$	71,833	$	19,850	$	91,683