Capital Stock - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended				1 Months Ended	12 Months Ended				12 Months Ended						1 Months Ended	12 Months Ended		12 Months Ended
	Aug. 09, 2013	May 17, 2013	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Jun. 29, 2012	May 17, 2013 Common Stock [Member]	Dec. 31, 2013 Common Stock [Member]	Dec. 31, 2012 Common Stock [Member]	Dec. 31, 2013 Convertible Preferred Stock [Member]	Dec. 31, 2013 Employee Stock Purchase Plan [Member]	Dec. 31, 2013 Warrant 2 [Member]	Dec. 31, 2013 Warrant 3 [Member]	Dec. 31, 2013 Warrant 4 [Member]	Dec. 31, 2013 Series A-1 Preferred Stock [Member]	May 17, 2013 Series A-1 Preferred Stock [Member]	Jun. 29, 2012 Series A-1 Preferred Stock [Member]	Jun. 29, 2012 Series B Preferred Stock [Member]	Dec. 31, 2013 Series B Preferred Stock [Member]	May 17, 2013 Series B Preferred Stock [Member]	Dec. 31, 2013 Placement Agent Warrants [Member]	Aug. 09, 2013 Placement Agent Warrants [Member]	May 17, 2013 Placement Agent Warrants [Member]
Stockholders Equity [Line Items]
Convertible preferred stock, par value			$ 0.001		$ 0.001
Convertible preferred stock, shares authorized			6,000,000		6,000,000
Convertible preferred stock, shares issued			0		5,500,000												5,000,000	500,000
Common stock, shares authorized	150,000,000	150,000,000	300,000,000		150,000,000
Common stock, par value			$ 0.001		$ 0.001
Common stock, outstanding or reserved for issuance																			198,521,806
Common stock, shares outstanding			122,448,707		36,761,864
Shares reserved for conversion of Preferred to common stock															28,160,200
Shares reserved for potential exercise										6,288,950
Shares reserved for exercise of outstanding warrants						437,158						1,750,000	437,158	35,081,967
Warrants exercise price per share		0.2745				0.2745						1.30	0.2745	0.2745							0.2745
Expiration date of warrants												Mar. 05, 2015	Jun. 29, 2017
Proceeds from private placement of preferred stock		$ 12,000,000	$ 12,000,000				$ 12,000,000											$ 3,000,000
Convertible preferred stock current conversion price			$ 0.3196																$ 0.2745
Net Proceeds from issuance of Series B Convertible preferred Stock																		2,700,000
Convertible preferred stock, liquidation preference		24,000,000			24,000,000											18,000,000				6,000,000
Convertible preferred stock, effective purchase price															$ 1.80				$ 6.00
Shares Reserved For Exercise Of Rights											638,887
Class Of Warrant Or Right Exercisable Number Of Warrants Or Rights		32,786,885												20,655,737
Warrant Exercisable Expiration Date			Jun. 30, 2014											May 17, 2020
Warrant Exercisable Remaining Expiration Date														Aug. 09, 2020
Shares Reserved For Issuance Of Common Stock And Warrants			31,876,137
Additional Pro Rata InvestmentIn Common Stock And Warrants			5,000,000					5,000,000
Fair Value Adjustment of Warrants			104,907
Conversion of Stock, Shares Converted			39,089,161																10,928,961
Convertible Preferred Stock, Shares Issued upon Conversion								39,089,161
Stock Issued During Period Shares New Issues							43,715,847		0
Share Price							$ 0.2745
Percentage Of Warrants Exercisable			63.00%
Percentage Of Warrants Exercisable After Shareholder Approval			37.00%
NoncashInterest Expense																					286,579
Increase In Common Stock Shares Authorized	300,000,000	300,000,000
Increase In Interest Expense	11,000
Allocated Share-based Compensation Expense																					780,000
Warrants To Purchase Of Common Stock																					2,295,082
Warrants Fair Value Disclosure				$ 5,358,708																		$ 5,369,676	$ 5,072,129