Summary of Significant Accounting Policies - Additional Information (Details) (USD $)	12 Months Ended
	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
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	47,000	33,000
Gross value of demos and loaners	1,400,000	1,600,000
Accumulated amortization on inventory demos and loaners	524,000	601,000
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	200,000	100,000	200,000
Release of deferred tax assets valuation allowance	(9,200,000)
Accrued interest and penalty incurred	$ 0
Customer accounted percentage of net accounts receivable balance	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	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	1	0