|
Significant Accounting Policies - Summary of Revenues (Detail) (USD $)
In Thousands, unless otherwise specified
|
12 Months Ended |
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
| Investment Holdings [Line Items] |
|
|
|
| Royalty revenue |
$ 2,562 |
$ 3,317 |
|
| Collaborative and other research and development revenues: |
|
|
|
| Collaborative and other research and development |
14,769 |
22,976 |
19,643 |
| Total revenues |
17,331 |
26,293 |
19,643 |
|
U.S. Department of Health and Human Services [Member]
|
|
|
|
| Collaborative and other research and development revenues: |
|
|
|
| Collaborative and other research and development |
13,585 |
14,026 |
17,099 |
|
Shionogi & Co. Ltd [Member]
|
|
|
|
| Collaborative and other research and development revenues: |
|
|
|
| Collaborative and other research and development |
1,184 |
1,184 |
1,181 |
|
Mundipharma (United Kingdom) [Member]
|
|
|
|
| Collaborative and other research and development revenues: |
|
|
|
| Collaborative and other research and development |
|
7,766 |
1,277 |
|
Grants (United States) [Member]
|
|
|
|
| Collaborative and other research and development revenues: |
|
|
|
| Collaborative and other research and development |
|
|
$ 86 |