Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Revenues	$ 1,409,432	$ 1,105,999	$ 4,019,928	$ 3,199,332
Cost of revenues	954,394	798,900	2,738,428	2,296,526
Marketing	145,654	108,228	403,515	341,925
Technology and development	120,953	95,540	346,445	280,641
General and administrative	78,024	46,211	193,938	134,181
Operating income	110,407	57,120	337,602	146,059
Other income (expense):
Interest expense	(13,486)	(7,436)	(36,866)	(21,704)
Interest and other income (expense)	616	(193)	3,117	(2,156)
Loss on extinguishment of debt	0	0	0	(25,129)
Income before income taxes	97,537	49,491	303,853	97,070
Provision for income taxes	38,242	17,669	120,425	33,088
Net income	$ 59,295	$ 31,822	$ 183,428	$ 63,982
Earnings per share:
Basic (in dollars per share)	$ 0.99	$ 0.54	$ 3.06	$ 1.11
Diluted (in dollars per share)	$ 0.96	$ 0.52	$ 2.97	$ 1.06
Weighted-average common shares outstanding:
Basic (in shares)	60,171	59,108	59,996	57,769
Diluted (in shares)	61,820	60,990	61,669	60,578