Stock-based Compensation (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Schedule of total stock-based compensation expense        
Total stock-based compensation expense $ 520 $ 232 $ 1,503 $ 640
Research and development [Member]
       
Schedule of total stock-based compensation expense        
Total stock-based compensation expense 146 75 373 205
Sales and marketing [Member]
       
Schedule of total stock-based compensation expense        
Total stock-based compensation expense 119 51 292 141
General and administrative [Member]
       
Schedule of total stock-based compensation expense        
Total stock-based compensation expense $ 255 $ 106 $ 838 $ 294