Employee Benefit Plans (Tables)

9 Months Ended

Sep. 27, 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				Nine months ended
	September 27, 2020		September 29, 2019		September 27, 2020		September 29, 2019
Pension and SERPA Benefits:
Service cost	$	6,806	$	6,072	$	20,418	$	19,336
Interest cost	19,112		21,371		57,335		64,113
Expected return on plan assets	(33,764)		(35,581)		(101,292)		(106,743)
Amortization of unrecognized:
Prior service credit	(272)		(483)		(816)		(1,449)
Net loss	16,372		11,128		49,116		33,384
Settlement loss	—		1,500		—		1,500
Net periodic benefit cost	$	8,254	$	4,007	$	24,761	$	10,141
Postretirement Healthcare Benefits:
Service cost	$	1,202	$	1,040	$	3,605	$	3,409
Interest cost	2,336		2,938		7,008		8,814
Expected return on plan assets	(3,467)		(3,507)		(10,401)		(10,521)
Amortization of unrecognized:
Prior service credit	(595)		(595)		(1,785)		(1,785)
Net loss	123		69		369		207
Special retirement benefit cost	—		—		—		1,583
Curtailment gain	—		—		—		(960)
Net periodic benefit cost	$	(401)	$	(55)	$	(1,204)	$	747