Reorganization and Realignment Costs G&A Realignment Costs (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
Reorganization and realignment costs	$ 3,375	$ 403	$ 10,196	$ 4,771
G&A Realignment
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	(80)	297	82	3,582
Restructuring and Related Cost, Cost Incurred to Date	29,046		29,046
Reorganization and realignment costs	(49)	396	282	4,695
Restructuring Charges, Incurred to Date	38,479		38,479
G&A Realignment | Severance and related employee costs
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	(116)	214	30	2,816
Restructuring and Related Cost, Cost Incurred to Date	24,268		24,268
G&A Realignment | Recruitment and relocation costs
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	27	58	42	654
Restructuring and Related Cost, Cost Incurred to Date	2,558		2,558
G&A Realignment | Third-party and other costs
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	9	25	10	112
Restructuring and Related Cost, Cost Incurred to Date	2,220		2,220
G&A Realignment | Share based compensation
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	31	99	200	1,113
Restructuring and Related Cost, Cost Incurred to Date	8,098		8,098
G&A Realignment | Termination of defined benefit plans
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	0	$ 0	0	$ 0
Restructuring and Related Cost, Cost Incurred to Date	$ 1,335		$ 1,335