Acquisitions (Details Textual) $ in Thousands	6 Months Ended
	Jul. 02, 2016 USD ($) acquisition
Business Acquisition [Line Items]
Goodwill acquired during period	$ 23,579
Acquired definite-lived intangible assets, weighted average useful life	8 years
2016 Acquisitions [Member]
Business Acquisition [Line Items]
Number of businesses acquired | acquisition	2
Total cash consideration, net of cash acquired	$ 42,400
Cash acquired from acquisition	1,800
Goodwill acquired during period	23,600
Finite-lived intangible assets acquired	23,200
Recognized identifiable assets acquired and liabilities assumed, net	$ (2,600)
Trust For Benefit Of Children of Chief Executive Officer [Member] | Rocketick Technologies [Member]
Business Acquisition [Line Items]
Related party, ownership percentage in acquired company	2.00%