Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended		3 Months Ended		9 Months Ended		64 Months Ended
	Sep. 30, 2016	Aug. 14, 2013	Aug. 31, 2014	Mar. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015	Jun. 06, 2011	Jun. 30, 2010
Stockholders Equity [Line Items]
Warrant exercise price		$ 10.00
Issuance of common stock in connection with common stock offerings (in shares)		834,847
Shares issued, price per share		$ 8.50
Common stock reserved for future issuance	4,131,706				4,131,706		4,131,706		4,131,706
Unrecognized compensation expense	$ 1.7				$ 1.7		$ 1.7		$ 1.7
Unrecognized stock-based compensation expense, weighted average period of recognition							2 years 3 months 11 days
Shares excluded from calculation of diluted net loss per share					3,129,479	2,323,430	3,129,479	2,323,430
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	2.0				$ 2.0		$ 2.0		2.0	$ 2.2
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax								$ 0.5
Restricted Stock Units (RSUs)
Stockholders Equity [Line Items]
Unrecognized compensation expense	$ 2.1				$ 2.1		$ 2.1		$ 2.1
Unrecognized stock-based compensation expense, weighted average period of recognition							2 years 10 months 21 days
2010 Plan
Stockholders Equity [Line Items]
Common stock reserved for future issuance												300,000
2011 Plan
Stockholders Equity [Line Items]
Common stock reserved for future issuance											400,000
Number of shares available for grant											859,956
Increase in shares of common stock authorized for issuance									3,000,000
2011 Plan | Restricted Stock Units (RSUs)
Stockholders Equity [Line Items]
Aggregate restricted stock units outstanding	1,631,266				1,631,266		1,631,266		1,631,266
2007 Plan and 2010 Plan
Stockholders Equity [Line Items]
Number of shares available for grant											459,956
Private Placement Investors
Stockholders Equity [Line Items]
Number of additional common stock to be purchased by the warrant		834,847
Consultant Warrant
Stockholders Equity [Line Items]
Warrant exercise price	$ 10.70		$ 10.70		$ 10.70		$ 10.70		$ 10.70
Warrants expiration date							Aug. 13, 2019
Warrants exercised	0				0		0		0
Opus Warrant
Stockholders Equity [Line Items]
Warrant exercise price	$ 2.19				$ 2.19		$ 2.19		$ 2.19
Warrants expiration date							Mar. 31, 2019
Opus Warrant | Opus Bank
Stockholders Equity [Line Items]
Number of additional common stock to be purchased by the warrant							100,000
Warrant exercise price				$ 9.90
Warrants expiration date							Mar. 31, 2019
Warrants exercised	0				0		0		0
Increase in number of shares common stock underlying warrants							200,000
Decrease in warrant exercise price per share							$ 2.19
Terms of new warrants issues							The terms of any new warrants issued will be identical to those of the existing warrant, except that each new warrant issued will be exercisable for 100,000 shares and have an exercise price equal to the average closing price of the Company’s common stock for the five trading days ending on the last day of the quarter with respect to which the new warrant is issued. In addition, the existing registration rights agreement was amended to include the new warrants and change the circumstances under which the Company must register shares underlying the warrants issued to Opus (the “Amended Rights Agreement”).
Warrants issued and excisable	100,000				100,000		100,000		100,000
New Opus Warrant
Stockholders Equity [Line Items]
Number of additional common stock to be purchased by the warrant	100,000
Warrant exercise price	$ 2.22				$ 2.22		$ 2.22		$ 2.22
Warrants expiration date							Sep. 30, 2021
Maximum | Consultant Warrant
Stockholders Equity [Line Items]
Number of additional common stock to be purchased by the warrant			85,000
Maximum | Opus Warrant | Opus Bank
Stockholders Equity [Line Items]
Number of additional common stock to be purchased by the warrant				100,000