CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Selling and marketing with a related party	$ 56,162	$ 57,258	$ 171,286	$ 164,339
Cost of revenue
Stock-based compensation	887	781	2,712	2,503
Selling and marketing
Stock-based compensation	3,943	2,881	11,857	10,574
Technology and content
Stock-based compensation	5,372	3,957	15,459	12,115
General and administrative
Stock-based compensation	7,837	7,719	22,532	23,718
Acquisition-related and other
Stock-based compensation			$ 56,643