Stock-Based Compensation - Schedule of Allocation of Recognized Period Cost (Details) - USD ($)	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total costs and expenses	$ 432,000	$ 318,000
Stock-based compensation, capitalized costs	0	0
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total costs and expenses	34,000	33,000
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total costs and expenses	183,000	139,000
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total costs and expenses	$ 215,000	$ 146,000