Pension Benefits - Changes in Benefit Obligation and Plan Assets (Details) - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2021	Dec. 27, 2020	Dec. 29, 2019
Change in benefit obligation
Benefit obligation at beginning of year	$ 1,808,605	$ 1,908,035
Service cost	9,200	10,548	$ 5,231
Interest cost	34,869	50,311	67,255
Actuarial (gain)/loss	(50,645)	174,288
Curtailments	(163)	(562)
Settlements	0	(236,282)
Benefits paid	(86,805)	(97,877)
Effects of change in currency conversion	(107)	144
Benefit obligation at end of year	1,714,954	1,808,605	1,908,035
Defined contribution plan, cost recognized	33,000	27,000	27,000
Change in plan assets
Fair value of plan assets at beginning of year	1,585,221	1,648,667
Actual return on plan assets	25,651	245,606
Employer contributions	26,011	25,107
Settlements	0	(236,282)
Benefits paid	(86,805)	(97,877)
Fair value of plan assets at end of year	1,550,078	1,585,221	1,648,667
Amount recognized in the Consolidated Balance Sheets
Noncurrent Assets	87,601	54,950
Current liabilities	(16,669)	(16,990)
Noncurrent liabilities	(235,808)	(261,344)
Net amount recognized	(164,876)	(223,384)
Amount recognized in accumulated other comprehensive loss
Actuarial loss	549,534	602,619
Prior service credit	(12,365)	(14,255)
Total	537,169	588,364
Qualified Plan
Change in benefit obligation
Benefit obligation at beginning of year	1,549,012	1,660,287
Service cost	9,105	10,429	5,113
Interest cost	30,517	43,710	58,835
Actuarial (gain)/loss	(42,883)	153,136
Curtailments	0	0
Settlements	0	(236,282)
Benefits paid	(69,987)	(82,268)
Effects of change in currency conversion	0	0
Benefit obligation at end of year	1,475,764	1,549,012	1,660,287
Change in plan assets
Fair value of plan assets at beginning of year	1,585,221	1,648,667
Actual return on plan assets	25,651	245,606
Employer contributions	9,193	9,498
Settlements	0	(236,282)
Benefits paid	(69,987)	(82,268)
Fair value of plan assets at end of year	1,550,078	1,585,221	1,648,667
Amount recognized in the Consolidated Balance Sheets
Noncurrent Assets	87,601	54,950
Current liabilities	0	0
Noncurrent liabilities	(13,287)	(18,741)
Net amount recognized	74,314	36,209
Amount recognized in accumulated other comprehensive loss
Actuarial loss	426,874	464,922
Prior service credit	(12,952)	(14,897)
Total	413,922	450,025
Nonqualified Plan
Change in benefit obligation
Benefit obligation at beginning of year	259,593	247,748
Service cost	95	119	118
Interest cost	4,352	6,601	8,420
Actuarial (gain)/loss	(7,762)	21,152
Curtailments	(163)	(562)
Settlements	0	0
Benefits paid	(16,818)	(15,609)
Effects of change in currency conversion	(107)	144
Benefit obligation at end of year	239,190	259,593	247,748
Change in plan assets
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	16,818	15,609
Settlements	0	0
Benefits paid	(16,818)	(15,609)
Fair value of plan assets at end of year	0	0	$ 0
Amount recognized in the Consolidated Balance Sheets
Noncurrent Assets	0	0
Current liabilities	(16,669)	(16,990)
Noncurrent liabilities	(222,521)	(242,603)
Net amount recognized	(239,190)	(259,593)
Amount recognized in accumulated other comprehensive loss
Actuarial loss	122,660	137,697
Prior service credit	587	642
Total	$ 123,247	$ 138,339