Property and Equipment - Net (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2014
Dec. 31, 2013
Schedule of property and equipment    
Property and equipment-gross $ 35,486 $ 30,730
Less accumulated depreciation (19,950) [1] (16,645) [1]
Total property and equipment—net 15,536 14,085
Computer equipment [Member]
   
Schedule of property and equipment    
Property and equipment-gross 20,920 [2] 19,361 [2]
Computer software [Member]
   
Schedule of property and equipment    
Property and equipment-gross 5,241 4,625
Furniture and fixtures [Member]
   
Schedule of property and equipment    
Property and equipment-gross 1,772 1,634
Leasehold improvements [Member]
   
Schedule of property and equipment    
Property and equipment-gross 1,232 1,044
Work in process [Member]
   
Schedule of property and equipment    
Property and equipment-gross 6,148 3,893
Other [Member]
   
Schedule of property and equipment    
Property and equipment-gross $ 173 $ 173
[1] Includes $2.1 million and $3.0 million of accumulated depreciation of equipment under capital leases as of December 31, 2013 and September 30, 2014, respectively.
[2] Includes equipment under capital lease obligations of $5.3 million and $6.7 million as of December 31, 2013 and September 30, 2014, respectively.