Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Jan. 02, 2016 USD ($) Customer	Jan. 03, 2015 USD ($) Customer	Dec. 28, 2013 USD ($) Customer	Dec. 29, 2012 USD ($)
Disclosure Summary Of Significant Accounting Policies [Line Items]
Restricted cash				$ 510,000
Percentage of purchase price to be deposited in escrow account				10.00%
Provision of sales returns	$ 60,000	$ 47,000
Gross value of demos and loaners	1,600,000	1,400,000
Accumulated amortization on inventory demos and loaners	$ 575,000	524,000
Estimated useful life of demos and loaners	4 years
Estimated useful lives of the assets			3 years
Products warranty period	2 years
Shipping and handling costs	$ 300,000	300,000	$ 300,000
Advertising and promotion costs	100,000	$ 200,000	$ 100,000
Accrued interest and penalty incurred	$ 0
Customer accounted percentage of net accounts receivable balance	10.00%	13.00%	10.00%
Revenue, Total | Customer Concentration Risk
Disclosure Summary Of Significant Accounting Policies [Line Items]
Number of customer accounted for total revenues and net accounts receivable | Customer	0	0	0
Customer accounted percentage of total revenues	10.00%	10.00%	10.00%
Accounts Receivable | Credit Concentration Risk
Disclosure Summary Of Significant Accounting Policies [Line Items]
Number of customer accounted for total revenues and net accounts receivable | Customer	0	1