|
Stock Plans (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2015
|
Mar. 31, 2014
|
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Total stock-based compensation expenses | $ 491 | $ 326 |
| Research and development [Member] | ||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Total stock-based compensation expenses | 203 | 145 |
| General and administrative [Member] | ||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
| Total stock-based compensation expenses | $ 288 | $ 181 |