Net (Loss) Income Per Share - Potentially Dilutive Securities Excluded from Diluted Net (Loss) Income Per Share (Detail) - shares
|
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Potential dilutive securities excluded from diluted net income (loss) per share attributable to common stockholders, Total |
5,323,480
|
1,984,586
|
753,322
|
| Shares of common stock subject to outstanding options [Member] |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Potential dilutive securities excluded from diluted net income (loss) per share attributable to common stockholders, Total |
1,757,309
|
1,577,317
|
539,645
|
| Shares of common stock subject to outstanding common stock warrants [Member] |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Potential dilutive securities excluded from diluted net income (loss) per share attributable to common stockholders, Total |
3,259,926
|
301,069
|
213,677
|
| Restricted Stock Units (RSUs) [Member] |
|
|
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |
|
|
|
| Potential dilutive securities excluded from diluted net income (loss) per share attributable to common stockholders, Total |
306,245
|
106,200
|
0
|