Property and Equipment, Net - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment-at cost | $ 5,600 | $ 5,223 |
| Less accumulated depreciation | (2,916) | (3,058) |
| Property and equipment-net | 2,684 | 2,165 |
| Office and Computer Equipment [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment-at cost | 705 | 503 |
| Laboratory Equipment [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment-at cost | 4,161 | 3,209 |
| Leasehold Improvements [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment-at cost | 257 | 887 |
| Furniture and Fixtures [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment-at cost | $ 477 | $ 624 |