Restructuring - Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	$ (97)	$ 4,252	$ 2,738	$ 6,626
Cumulative To Date	78,856		78,856
December 2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	(104)	0	2,784	0
Cumulative To Date	10,180		10,180
February 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	7	4,218	19	6,622
Cumulative To Date	13,612		13,612
Legacy Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Business reorganization costs			(65)
Legacy restructuring plan charges (credits) | February 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	0	3,527	0	5,874
Cumulative To Date	5,874		5,874
Legacy restructuring plan charges (credits) | Legacy Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	0	34	(65)	4
Cumulative To Date	55,064		55,064
Severance and benefit charges (credits) | December 2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	(104)	0	2,784	0
Cumulative To Date	10,139		10,139
Severance and benefit charges (credits) | February 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	0	(12)	0	(46)
Cumulative To Date	6,210		6,210
Lease and related termination costs | February 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	0	213	(26)	213
Cumulative To Date	528		528
Other costs (credits)1 | December 2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	0	0	0	0
Cumulative To Date	41		41
Other costs (credits)1 | February 2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Business reorganization costs	7	$ 490	45	$ 581
Cumulative To Date	$ 1,000		$ 1,000