Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020		Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ 1,755,441	$ 1,801,139	$ 1,815,705	[1]	$ 1,772,278
Other comprehensive (loss)/income	39,110	11,071	(54,877)		17,119
Ending Balance	1,807,704	1,853,620	1,807,704		1,853,620
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance			(241,994)		(251,102)
Other comprehensive income/(loss) before reclassifications			(60,121)		6,721
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax			0
Other comprehensive (loss)/income			(60,121)		6,721
Ending Balance	(302,115)	(244,381)	(302,115)		(244,381)
Foreign Currency Items | Fixed Assets
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					0
Foreign Currency Items | Net Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					0
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance			(574,413)		(487,380)
Other comprehensive income/(loss) before reclassifications			(862)		(5,939)
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax			11,058
Other comprehensive (loss)/income			10,196		8,963
Ending Balance	(564,217)	(478,417)	(564,217)		(478,417)
Defined Benefit Pension Items | Fixed Assets
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					0
Defined Benefit Pension Items | Net Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					14,902
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance			(396)		(2,431)
Other comprehensive income/(loss) before reclassifications			(4,402)		1,726
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax			1,677
Other comprehensive (loss)/income			(2,725)		1,383
Ending Balance	(3,121)	(1,048)	(3,121)		(1,048)
Cash Flow Hedges | Fixed Assets
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					(101)
Cash Flow Hedges | Net Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					(242)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(909,153)	(734,745)	(816,803)		(740,913)
Other comprehensive income/(loss) before reclassifications			(65,385)		2,508
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax			12,735
Other comprehensive (loss)/income			(52,650)		17,067
Ending Balance	$ (869,453)	$ (723,846)	$ (869,453)		(723,846)
Accumulated Other Comprehensive Loss | Fixed Assets
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					(101)
Accumulated Other Comprehensive Loss | Net Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amounts reclassified from accumulated other comprehensive income/(loss) net of tax					$ 14,660

[1] The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America.