Related Party Transactions (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Related Party Transactions [Abstract]      
Number of companies that will work together to conduct research and development and other activities 2    
Related party transactions      
Accounts receivable $ 231 $ 1,036  
The entity whose vice chairman of the board of directors is a director of the company and is also a managing member of a significant shareholder of the company | CDP Agreement
     
Related party transactions      
Percentage of beneficial ownership interest of the entity's common stock 9.20%    
Accounts receivable 100 400  
Deferred revenue balance 0 100  
Related party revenue 4,365 4,544 5,237
The entity whose independent board member serves the company's board of directors | Alliance Agreement
     
Related party transactions      
Percentage of beneficial ownership interest of the entity's common stock 5.60%    
Accounts receivable 100 600  
Deferred revenue balance 400 700  
Related party revenue 8,449 16,524 15,756
Related cost of revenue $ 4 $ 55 $ 78