Goodwill - Changes in the Carrying Value of Goodwill (Details) $ in Thousands	6 Months Ended
	Jul. 02, 2017 USD ($)
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 95,280
Goodwill, Ending Balance	115,089
ViDi Systems S.A.
Goodwill [Line Items]
Acquisition of ViDi Systems S.A.	18,333
Acquisition of GVi Ventures, Inc.	18,333
GVi Ventures, Inc.
Goodwill [Line Items]
Acquisition of ViDi Systems S.A.	1,476
Acquisition of GVi Ventures, Inc.	$ 1,476