Redeemable Convertible Preferred Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Class of Stock [Line Items] | |||
| Preferred stock, shares outstanding | 0 | 0 | |
| Conversion of Redeemable Preferred Stock | 10.47-for-1 basis | ||
| Preferred stock, shares issued | 0 | 0 | |
| Preferred stock, proceeds from issuance | $ 35,406 | ||
| Common stock, issuance cost | $ 3,304 | $ 30 | |
| Series E Redeemable Convertible Preferred Stock [Member] | |||
| Class of Stock [Line Items] | |||
| Preferred stock, shares issued | 56,892,391 | ||
| Preferred stock, issuance price per share | $ 0.62398475 | ||
| Preferred stock, proceeds from issuance | $ 35,500 | ||
| Common stock, issuance cost | $ 94 | ||
| Series A, B-1, B-2, C,D-1, D-2, D-3 and E Redeemable Convertible Preferred Stock [Member] | |||
| Class of Stock [Line Items] | |||
| Preferred stock, shares outstanding | 0 | 0 | |