v2.4.0.8
Segment Information and Information about Geographic Area (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2013
segment
Dec. 31, 2012
Dec. 31, 2011
Segment Reporting Information [Line Items]                      
Number of operating segments                 1    
Revenues $ 29,039 $ 27,749 $ 26,291 $ 24,883 $ 24,657 $ 23,382 $ 22,190 $ 21,191 $ 107,962 $ 91,420 $ 76,212
Property and equipment, net 23,075       18,148       23,075 18,148  
United States
                     
Segment Reporting Information [Line Items]                      
Revenues                 75,485 62,616 51,044
Property and equipment, net 19,909       16,495       19,909 16,495  
Other
                     
Segment Reporting Information [Line Items]                      
Revenues                 32,477 28,804 25,168
Property and equipment, net $ 3,166       $ 1,653       $ 3,166 $ 1,653