Restructuring (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 3,126	$ 4,376	$ 4,467	$ 5,405
Impairment of operating lease right-of-use asset (recorded in Restructuring charges)			977	0
Q2 2019 Sales Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,400
June 2018 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4,100		4,100
June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges	700	$ 300	2,000	$ 1,300
Restructuring and related cost, cost incurred to date	18,400		18,400
Minimum | June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	21,500		21,500
Maximum | June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	$ 23,000		23,000
Lease Termination & Fixed Assets | June 2017 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 700
Percentage of facility vacated			100.00%
Impairment of operating lease right-of-use asset (recorded in Restructuring charges)			$ 200
Hyderabad
Restructuring Cost and Reserve [Line Items]
Ownership percentage					100.00%