Stock Plans (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | |
---|---|---|
Mar. 31, 2014
|
Mar. 31, 2013
|
|
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
Total stock-based compensation expenses | $ 326 | $ 505 |
Research and Development Expense [Member]
|
||
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
Total stock-based compensation expenses | 145 | 304 |
General and Administrative Expense [Member]
|
||
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||
Total stock-based compensation expenses | $ 181 | $ 201 |