Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2019

Retirement Benefits [Abstract]

Components of net periodic benefit cost

The components of net periodic benefit cost include the following:

	Three Months Ended				Six Months Ended
	June 30, 2019		July 1, 2018		June 30, 2019		July 1, 2018
Retirement Plans
Service cost	$	962	$	4,478	$	1,903	$	9,150
Interest cost	15,100		13,573		30,043		27,551
Expected return on plan assets	(19,232)		(22,580)		(38,329)		(45,789)
Amortization of prior service cost	216		242		430		491
Amortization of net actuarial loss	9,646		9,162		18,680		18,582
Effect of settlement loss	225		645		1,547		645
Net periodic benefit cost	$	6,917	$	5,520	$	14,274	$	10,630
Retiree Health and Life Insurance Plans
Service cost	$	78	$	70	$	152	$	149
Interest cost	113		110		231		221
Expected return on plan assets	(179)		(218)		(356)		(690)
Amortization of prior service credit	(124)		(123)		(247)		(249)
Amortization of net actuarial gain	(215)		(298)		(408)		(540)
Net periodic benefit income	$	(327)	$	(459)	$	(628)	$	(1,109)