Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 5,078	$ 182	$ 532
Restructuring charges	9,267	19,239	10
Costs paid or otherwise settled	(12,471)	(14,343)	(367)
Adjustments to prior restructuring costs			7
Ending Balance	1,874	5,078	182
Severance and related
Restructuring Reserve [Roll Forward]
Beginning Balance	3,696	0	17
Restructuring charges	2,883	12,861	0
Costs paid or otherwise settled	(5,778)	(9,165)	(8)
Adjustments to prior restructuring costs			(9)
Ending Balance	801	3,696	0
Lease termination
Restructuring Reserve [Roll Forward]
Beginning Balance	1,005	43	368
Restructuring charges	2,993	2,667	1
Costs paid or otherwise settled	(2,962)	(1,705)	(341)
Adjustments to prior restructuring costs			15
Ending Balance	1,036	1,005	43
Software Contracts & Engineering Tools
Restructuring Reserve [Roll Forward]
Beginning Balance	377	0	0
Restructuring charges	1,903	3,040	0
Costs paid or otherwise settled	(2,255)	(2,663)	0
Adjustments to prior restructuring costs			0
Ending Balance	25	377	0
Other
Restructuring Reserve [Roll Forward]
Beginning Balance	0	139	147
Restructuring charges	1,488	671	9
Costs paid or otherwise settled	(1,476)	(810)	(18)
Adjustments to prior restructuring costs			1
Ending Balance	$ 12	$ 0	$ 139