Employee Benefit Plans (Tables)

6 Months Ended

Jun. 28, 2020

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Costs

Components of net periodic benefit cost for the Company's defined benefit plans were as follows (in thousands):

	Three months ended				Six months ended
	June 28, 2020		June 30, 2019		June 28, 2020		June 30, 2019
Pension and SERPA Benefits:
Service cost	$	6,806	$	6,632	$	13,612	$	13,264
Interest cost	19,111		21,371		38,223		42,742
Expected return on plan assets	(33,764)		(35,581)		(67,528)		(71,162)
Amortization of unrecognized:
Prior service credit	(272)		(483)		(544)		(966)
Net loss	16,372		11,128		32,744		22,256
Net periodic benefit cost	$	8,253	$	3,067	$	16,507	$	6,134
Postretirement Healthcare Benefits:
Service cost	$	1,202	$	1,185	$	2,403	$	2,369
Interest cost	2,336		2,938		4,672		5,876
Expected return on plan assets	(3,467)		(3,507)		(6,934)		(7,014)
Amortization of unrecognized:
Prior service credit	(595)		(595)		(1,190)		(1,190)
Net loss	123		69		246		138
Special retirement benefit cost	—		1,583		—		1,583
Curtailment gain	—		(960)		—		(960)
Net periodic benefit cost	$	(401)	$	713	$	(803)	$	802