Restructuring (Schedule of Restructuring Activities) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	$ 10,680	$ 2,447
Restructuring charges	4,467	5,405
Costs paid or otherwise settled	(5,494)	(3,074)
Accrued Restructuring at the end of the period	9,653	4,778
Severance & related
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	1,814	1,192
Restructuring charges	615	3,964
Costs paid or otherwise settled	(2,178)	(1,443)
Accrued Restructuring at the end of the period	251	3,713
Lease Termination & Fixed Assets
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	8,630	870
Restructuring charges	2,140	440
Costs paid or otherwise settled	(3,042)	(593)
Accrued Restructuring at the end of the period	7,728	717
Software Contracts & Engineering Tools
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	218	360
Restructuring charges	0	913
Costs paid or otherwise settled	(218)	(968)
Accrued Restructuring at the end of the period	0	305
Other
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	18	25
Restructuring charges	1,712	88
Costs paid or otherwise settled	(56)	(70)
Accrued Restructuring at the end of the period	$ 1,674	$ 43