Restructuring (Schedule of Restructuring Activities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	$ 10,680	$ 2,447
Restructuring charges	4,719	5,495
Costs paid or otherwise settled	(6,307)	(6,497)
Accrued Restructuring at the end of the period	9,092	1,445
Severance & related
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	1,814	1,192
Restructuring charges	625	4,034
Costs paid or otherwise settled	(2,279)	(4,662)
Accrued Restructuring at the end of the period	160	564
Lease Termination & Fixed Assets
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	8,630	870
Restructuring charges	2,482	437
Costs paid or otherwise settled	(3,714)	(667)
Accrued Restructuring at the end of the period	7,398	640
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)	(1,055)
Accrued Restructuring at the end of the period	0	218
Other
Restructuring Reserve [Roll Forward]
Accrued Restructuring at beginning of the period	18	25
Restructuring charges	1,612	111
Costs paid or otherwise settled	(96)	(113)
Accrued Restructuring at the end of the period	$ 1,534	$ 23