CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Selling and marketing with a related party	$ 54,053	$ 55,720	$ 115,124	$ 107,081
Cost of revenue
Stock-based compensation	764	803	1,825	1,722
Selling and marketing
Stock-based compensation	3,649	3,248	7,914	7,693
Technology and content
Stock-based compensation	4,692	3,874	10,087	8,158
General and administrative
Stock-based compensation	6,981	8,696	14,695	15,999
Acquisition-related and other
Stock-based compensation			$ 56,643