Consolidated Statements Of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Operations [Abstract]
Selling and marketing with a related party	$ 211,018	$ 171,110	$ 139,714
Stock-based compensation, Cost of revenue	2,971	2,401	2,285
Stock-based compensation, Selling and marketing	13,085	11,766	10,555
Stock-based compensation, Technology and content	13,505	11,665	13,424
Stock-based compensation, General and administrative	$ 34,286	$ 26,675	$ 29,492