Pension Benefits - Changes in Benefit Obligation and Plan Assets (Details) - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Change in benefit obligation
Benefit obligation at beginning of year	$ 1,714,464	$ 1,881,790
Service cost	5,231	10,065	$ 9,799
Interest cost	67,255	60,153	68,582
Plan participants’ contributions	0	3
Amendments	706	0
Actuarial loss/(gain)	223,978	(133,891)
Curtailments	(373)	(200)
Benefits paid	(103,209)	(103,398)
Effects of change in currency conversion	(17)	(58)
Benefit obligation at end of year	1,908,035	1,714,464	1,881,790
Change in plan assets
Fair value of plan assets at beginning of year	1,410,151	1,567,411
Actual return on plan assets	315,148	(81,529)
Employer contributions	26,577	27,664
Plan participants’ contributions	0	3
Benefits paid	(103,209)	(103,398)
Fair value of plan assets at end of year	1,648,667	1,410,151	1,567,411
Amount recognized in the Consolidated Balance Sheets
Current liabilities	(17,147)	(17,034)
Noncurrent liabilities	(242,221)	(287,279)
Net amount recognized	(259,368)	(304,313)
Amount recognized in accumulated other comprehensive loss
Actuarial loss	715,391	748,702
Prior service credit	(16,149)	(18,786)
Total	699,242	729,916
Qualified Plan
Change in benefit obligation
Benefit obligation at beginning of year	1,491,398	1,636,488
Service cost	5,113	9,986	9,720
Interest cost	58,835	52,770	60,742
Plan participants’ contributions	0	3
Amendments	0	0
Actuarial loss/(gain)	191,104	(123,670)
Curtailments	0	0
Benefits paid	(86,163)	(84,179)
Effects of change in currency conversion	0	0
Benefit obligation at end of year	1,660,287	1,491,398	1,636,488
Change in plan assets
Fair value of plan assets at beginning of year	1,410,151	1,567,411
Actual return on plan assets	315,148	(81,529)
Employer contributions	9,531	8,445
Plan participants’ contributions	0	3
Benefits paid	(86,163)	(84,179)
Fair value of plan assets at end of year	1,648,667	1,410,151	1,567,411
Amount recognized in the Consolidated Balance Sheets
Current liabilities	0	0
Noncurrent liabilities	(11,620)	(81,247)
Net amount recognized	(11,620)	(81,247)
Amount recognized in accumulated other comprehensive loss
Actuarial loss	592,774	654,579
Prior service credit	(16,842)	(18,786)
Total	575,932	635,793
Nonqualified Plan
Change in benefit obligation
Benefit obligation at beginning of year	223,066	245,302
Service cost	118	79	79
Interest cost	8,420	7,383	7,840
Plan participants’ contributions	0	0
Amendments	706	0
Actuarial loss/(gain)	32,874	(10,221)
Curtailments	(373)	(200)
Benefits paid	(17,046)	(19,219)
Effects of change in currency conversion	(17)	(58)
Benefit obligation at end of year	247,748	223,066	245,302
Change in plan assets
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	17,046	19,219
Plan participants’ contributions	0	0
Benefits paid	(17,046)	(19,219)
Fair value of plan assets at end of year	0	0	$ 0
Amount recognized in the Consolidated Balance Sheets
Current liabilities	(17,147)	(17,034)
Noncurrent liabilities	(230,601)	(206,032)
Net amount recognized	(247,748)	(223,066)
Amount recognized in accumulated other comprehensive loss
Actuarial loss	122,617	94,123
Prior service credit	693	0
Total	$ 123,310	$ 94,123