Net Loss per Share of Common Stock - Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Shares Outstanding (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted shares outstanding		8,115,039
Warrants to purchase convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted shares outstanding		173,910
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted shares outstanding	2,188,896	652,723