Preferred Stock, Common Stock and Stockholders' Equity - Stock-Based Compensation and Employee Stock Purchase Plan - Additional Information (Detail) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Jun. 13, 2013	Jan. 02, 2015	Dec. 31, 2013	Jan. 01, 2015
Stock-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 2,323,000
Weighted average period	1 year 3 months 26 days
Common stock reserved for issuance	1,043,457			769,250
Shares of common stock issued under ESPP	7,294
Employee stock purchase plan [Member]
Stock-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of deduction of eligible compensation		20.00%
Common stock reserved for issuance	52,706	30,000
Shares of common stock available for issuance description	In addition, the number of shares of common stock available for issuance under the ESPP is annually increased on the first day of each fiscal year during the term of the ESPP by an amount equal to the lesser of: (i) 30,000 shares; (ii) one percent of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company’s board of directors may determine.
Reserve percentage for issuance of shares		100.00%
ESPP approval date		Aug. 29, 2013
Subsequent Event [Member] | Employee stock purchase plan [Member]
Stock-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance					82,706
Stock issued during period, shares, period increase			30,000