Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 182	$ 532	$ 3,424
Restructuring charges	19,239	10	586
Costs paid or otherwise settled	(14,343)	(367)	(3,280)
Adjustments to prior restructuring costs	0	7	(198)
Ending Balance	5,078	182	532
Severance and related
Restructuring Reserve [Roll Forward]
Beginning Balance	0	17	2,373
Restructuring charges	12,861	0	109
Costs paid or otherwise settled	(9,165)	(8)	(2,315)
Adjustments to prior restructuring costs	0	(9)	(150)
Ending Balance	3,696	0	17
Lease termination
Restructuring Reserve [Roll Forward]
Beginning Balance	43	368	793
Restructuring charges	2,667	1	224
Costs paid or otherwise settled	(1,705)	(341)	(740)
Adjustments to prior restructuring costs	0	15	91
Ending Balance	1,005	43	368
System and Engineering Tools [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	0	0	0
Restructuring charges	3,040	0	0
Costs paid or otherwise settled	(2,663)	0	0
Adjustments to prior restructuring costs	0	0	0
Ending Balance	377	0	0
Other
Restructuring Reserve [Roll Forward]
Beginning Balance	139	147	258
Restructuring charges	671	9	253
Costs paid or otherwise settled	(810)	(18)	(225)
Adjustments to prior restructuring costs	0	1	(139)
Ending Balance	$ 0	$ 139	$ 147