Segments and Information about Revenues by Geographic Region (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Segment Reporting Information [Line Items]        
Revenues $ 104,469 $ 61,079 $ 269,693 $ 150,981
United States and Canada
       
Segment Reporting Information [Line Items]        
Revenues 80,360 49,887 208,730 122,905
International
       
Segment Reporting Information [Line Items]        
Revenues $ 24,109 $ 11,192 $ 60,963 $ 28,076