Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Share of Common Stock - Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail)

v3.7.0.1
Net Loss Per Share of Common Stock - Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail) - shares
6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares 26,309,857 18,169,370
Employee Stock Options [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares 6,036,984 4,689,120
Warrants [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares 20,272,873 13,480,250