Redeemable Convertible Preferred Stock - Additional Information (Detail) |
12 Months Ended | ||
|---|---|---|---|
|
Jul. 30, 2014
shares
|
Jul. 10, 2014 |
Dec. 31, 2014
shares
|
|
| Class of Stock [Line Items] | |||
| Reverse stock split ratio | 0.378 | ||
| Common Stock [Member] | |||
| Class of Stock [Line Items] | |||
| Number of common shares issued on conversion of redeemable convertible preferred stock | 12,440,205 | ||
| IPO [Member] | Common Stock [Member] | |||
| Class of Stock [Line Items] | |||
| Number of common shares issued on conversion of redeemable convertible preferred stock | 12,440,205 |