Property and Equipment - Net (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Schedule of property and equipment    
Property and equipment-gross $ 22,578 $ 17,113
Less accumulated depreciation (11,400) (8,812)
Total property and equipment-net 11,178 8,301
Computer equipment [Member]
   
Schedule of property and equipment    
Property and equipment-gross 16,640 13,032
Computer software [Member]
   
Schedule of property and equipment    
Property and equipment-gross 2,748 1,409
Furniture and fixtures [Member]
   
Schedule of property and equipment    
Property and equipment-gross 1,050 1,049
Leasehold improvements [Member]
   
Schedule of property and equipment    
Property and equipment-gross 718 690
Work in process [Member]
   
Schedule of property and equipment    
Property and equipment-gross 1,249   
Other [Member]
   
Schedule of property and equipment    
Property and equipment-gross $ 173 $ 933