Net Loss Per Share of Common Stock - Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail) - shares |
3 Months Ended | |
|---|---|---|
Mar. 31, 2017 |
Mar. 31, 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 | 26,242,224 | 18,214,615 |
| 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 | 5,907,782 | 4,711,508 |
| 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 | 20,334,442 | 13,503,107 |