Impairment and Restructuring Charges - Restructuring Accrual (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Restructuring Reserve
Beginning Accrual Balance			$ 7,043	$ 8,640
Additions Charged to Expense	$ 719	$ 4,851	4,455	11,719
Payments or Utilization			(9,837)	(13,076)
Ending Accrual Balance	1,661	7,283	1,661	7,283
Severance costs
Restructuring Reserve
Beginning Accrual Balance			5,314	5,353
Additions Charged to Expense			4,025	10,126
Payments or Utilization			(8,023)	(11,067)
Ending Accrual Balance	1,316	4,412	1,316	4,412
Other exit costs
Restructuring Reserve
Beginning Accrual Balance			1,729	3,287
Additions Charged to Expense			430	1,593
Payments or Utilization			(1,814)	(2,009)
Ending Accrual Balance	$ 345	$ 2,871	$ 345	$ 2,871