Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Revenues	$ 1,340,407	$ 1,069,372	$ 2,610,496	$ 2,093,333
Cost of revenues	914,848	760,674	1,784,034	1,497,626
Marketing	120,763	114,611	257,861	233,697
Technology and development	115,182	93,126	225,492	185,101
General and administrative	60,014	43,844	115,914	87,970
Operating income	129,600	57,117	227,195	88,939
Other income (expense):
Interest expense	(13,328)	(7,528)	(23,380)	(14,268)
Interest and other income (expense)	1,100	(2,940)	2,501	(1,963)
Loss on extinguishment of debt	0	0	0	(25,129)
Income before income taxes	117,372	46,649	206,316	47,579
Provision for income taxes	46,354	17,178	82,183	15,419
Net income	$ 71,018	$ 29,471	$ 124,133	$ 32,160
Earnings per share:
Basic (in dollars per share)	$ 1.18	$ 0.51	$ 2.07	$ 0.56
Diluted (in dollars per share)	$ 1.15	$ 0.49	$ 2.02	$ 0.53
Weighted-average common shares outstanding:
Basic (in shares)	59,996	58,192	59,907	57,089
Diluted (in shares)	61,634	60,590	61,592	60,369