Acquisitions (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) acquisition	Jan. 02, 2016 USD ($)	Jan. 03, 2015 USD ($)	Jun. 13, 2014 USD ($)
Business Acquisition [Line Items]
Cash paid in business combinations and asset acquisitions, net of cash acquired	$ 41,627	$ 0	$ 167,121
Goodwill resulting from acquisitions	23,579
Transaction costs associated with acquisitions	$ 1,100	$ 700	3,700
2016 Acquisitions [Member]
Business Acquisition [Line Items]
Number of businesses acquired | acquisition	2
Cash paid in business combinations and asset acquisitions, net of cash acquired	$ 42,400
Cash acquired	1,800
Goodwill resulting from acquisitions	23,600
Finite-lived intangible assets resulting from acquisitions	23,200
Net other identifiable assets and liabilities resulting from acquisitions	$ (2,600)
Weighted average useful life of finite-lived intangible assets resulting from acquisitions	8 years
Jasper [Member]
Business Acquisition [Line Items]
Total consideration paid, net of cash acquired				$ 139,400
Cash acquired				$ 28,700
Other 2014 Acquisitions [Member]
Business Acquisition [Line Items]
Cash paid in business combinations and asset acquisitions, net of cash acquired			27,500
Cash acquired			$ 2,100
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%