Employee Retirement Plans Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020 USD ($)	Jun. 29, 2019 USD ($)	Jun. 27, 2020 USD ($) plan	Jun. 29, 2019 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net Periodic Benefit Cost, Other Components	$ 9,766	$ 7,297	$ 19,855	$ 15,058
Number of defined contribution 401K savings plans | plan			2
Non-US Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	624	620	$ 1,269	1,246
Interest cost	6,212	8,349	12,630	16,781
Expected return on assets	(17,405)	(16,832)	(35,387)	(33,830)
Amortization of net (gain) loss	810	156	1,647	313
Amortization of prior service cost (credit)	617	642	1,255	1,290
Curtailment loss (gain)	0	388	0	388
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (9,142)	$ (6,677)	$ (18,586)	$ (13,812)