Stockholders' Equity (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Stock-based compensation related to stock-based awards to employees and nonemployees
Total stock-based compensation	$ 48,354	$ 19,323	$ 82,293	$ 31,949
Tax benefit from stock-based compensation	(13,465)	(3,762)	(22,754)	(6,603)
Total stock-based compensation, net of tax effect	34,889	15,561	59,539	25,346
Cost of revenue
Stock-based compensation related to stock-based awards to employees and nonemployees
Total stock-based compensation	3,913	1,236	6,719	2,037
Sales and marketing
Stock-based compensation related to stock-based awards to employees and nonemployees
Total stock-based compensation	8,843	4,327	15,704	7,195
Product development
Stock-based compensation related to stock-based awards to employees and nonemployees
Total stock-based compensation	24,885	10,572	42,523	16,461
General and administrative
Stock-based compensation related to stock-based awards to employees and nonemployees
Total stock-based compensation	$ 10,713	$ 3,188	$ 17,347	$ 6,256