|
Stock Based Compensation - Stock-Based Compensation Expense (Detail) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Jun. 30, 2013
|
Jun. 30, 2012
|
|
| Amortization of stock-based compensation: | ||||
| Stock-based compensation expense | $ 1,272 | $ 744 | $ 2,325 | $ 1,143 |
|
Research and development [Member]
|
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| Amortization of stock-based compensation: | ||||
| Stock-based compensation expense | 663 | 370 | 1,197 | 611 |
|
General and administrative [Member]
|
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| Amortization of stock-based compensation: | ||||
| Stock-based compensation expense | $ 609 | $ 374 | $ 1,128 | $ 532 |