SCHEDULE I CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY (Details 3) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Operating expenses      
General and administrative $ (136,863) $ (89,875) $ (38,533)
Selling and marketing (46,706) (27,741) (16,924)
Total operating expenses (182,671) (122,472) (57,281)
Interest expense (27) (70) (102)
Interest income 2,220 3,685 2,979
Net loss before income from subsidiaries and VIE 12,737 4,512 20,116
Equity in income of subsidiaries and VIE 68 23  
Parent Company
     
Operating expenses      
General and administrative (24,666) (23,074) (7,156)
Selling and marketing (925) (494) (533)
Total operating expenses (25,591) (23,568) (7,689)
Interest expense     (43)
Interest income 27 645 607
Net loss before income from subsidiaries and VIE (25,564) (22,923) (7,125)
Equity in income of subsidiaries and VIE 33,401 25,513 25,026
Net income $ 7,837 $ 2,590 $ 17,901