Summary of Significant Accounting Policies (Details 3) (USD $)
In Thousands, except Share data, unless otherwise specified
 1 Months Ended 9 Months Ended 9 Months Ended
Jun. 30, 2010
item
Sep. 30, 2013
Dec. 31, 2012
Sep. 30, 2013
Shares underlying outstanding options to purchase common stock
Sep. 30, 2012
Shares underlying outstanding options to purchase common stock
Sep. 30, 2013
Shares of unvested restricted stock and restricted stock units
Sep. 30, 2013
Shares underlying outstanding warrants to purchase common stock
Sep. 30, 2012
Shares underlying outstanding warrants to purchase common stock
Other Assets-Equipment Funding                
Number of monthly installments 14              
Other assets-equipment funding   $ 7,291 $ 6,763          
Amount capitalized under amended funding agreement   528            
Expected expenses based on exchange rates effect   $ 800            
Net Loss per Common Share                
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding because of anti-dilutive effect       1,398,886 2,911,632 1,769,690 10,916,216 200,268