Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 25, 2020	Dec. 27, 2019
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Total Cost	$ 274,306	$ 269,663
Total Foreign Currency Translation	(10,628)	(15,100)
Finite Life
Accumulated amortization	(103,018)	(91,940)
Total Book Value	160,660	162,623
Trade Names
Indefinite Life
Cost	61,920	61,920
Indefinite-lived Intangible Assets, Foreign Currency Translation Gain (Loss)	(1,572)	(3,730)
Book value	60,348	58,190
Customer Relationships
Finite Life
Cost	186,073	186,310
Accumulated amortization	(90,280)	(80,764)
Foreign currency translation	(8,349)	(10,412)
Book value	$ 87,444	$ 95,134
Weighted average life in years	13 years	13 years
Patents and Proprietary Technology
Finite Life
Cost	$ 25,313	$ 20,413
Accumulated amortization	(12,380)	(10,526)
Foreign currency translation	(707)	(885)
Book value	$ 12,226	$ 9,002
Weighted average life in years	10 years	10 years
Trademarks, Trade Names and Other
Finite Life
Cost	$ 1,000	$ 1,020
Accumulated amortization	(358)	(650)
Foreign currency translation	0	(73)
Book value	$ 642	$ 297
Weighted average life in years	4 years	4 years