Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended		6 Months Ended	9 Months Ended
	Sep. 28, 2013	Sep. 30, 2012	Sep. 28, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 28, 2013 Minimum	Sep. 28, 2013 Maximum	Sep. 28, 2013 IPO	Sep. 28, 2013 IPO	Sep. 30, 2012 IPO	Sep. 28, 2013 Existing Shareholders IPO
Schedule Of Significant Accounting Policies [Line Items]
Initial public offering, shares amount									7,762,500		2,250,000
Underwriters exercise of public offering overallotment shares									1,012,500
Initial public offering, price per share								$ 19.00	$ 19.00
Proceeds from initial public offering, net			$ 95,391,000	$ (572,000)					$ 93,400,000
Initial public offering, underwriting discounts and commissions									7,300,000
Other offering expenses			100,000					4,000,000	4,000,000	4,000,000
Conversion of redeemable convertible preferred units into common stock			8,100,000
(Recovery) write-down of Inventories	(200,000)	200,000	(382,000)	1,587,000
Deferred costs, current	$ 1,000,000		$ 1,000,000		$ 600,000
Services revenue, recognition period (in years)						1 year	5 years
Product warranties period (in years)			5 years
Stock split conversion ratio			0.33