|
Common Stock - Components of Stock-Based Compensation Expense (Detail) (USD $)
In Thousands, unless otherwise specified |
9 Months Ended | 87 Months Ended | |
|---|---|---|---|
|
Sep. 30, 2013
|
Sep. 30, 2012
|
Sep. 30, 2013
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Total stock-based compensation expense | $ 4,072 | $ 2,173 | $ 11,584 |
|
Employee Awards [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Total stock-based compensation expense | 3,174 | 1,336 | 6,380 |
|
Non-Employee Awards [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Total stock-based compensation expense | 758 | 412 | 4,171 |
|
Non-Employee Warrants [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Total stock-based compensation expense | $ 140 | $ 425 | $ 1,033 |