Net Loss Per Share of Common Stock - Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	17,421,356	7,466,180
Preferred Stock [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares		4,554,874
Equity Options [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	2,843,995	2,192,984
Class A Warrants [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	6,880,333
Class B Warrants [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	3,440,166
Warrants [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	4,256,862	718,322