Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Revenues	$ 1,105,999	$ 905,089	$ 3,199,332	$ 2,664,043
Cost of revenues	791,019	662,638	2,271,407	1,929,999
Marketing	116,109	108,448	367,044	352,340
Technology and development	95,540	82,521	280,641	246,869
General and administrative	46,211	35,347	134,181	104,481
Operating income	57,120	16,135	146,059	30,354
Other income (expense):
Interest expense	(7,436)	(4,990)	(21,704)	(14,970)
Interest and other income (expense)	(193)	801	(2,156)	192
Loss on extinguishment of debt	0	0	(25,129)	0
Income before income taxes	49,491	11,946	97,070	15,576
Provision for income taxes	17,669	4,271	33,088	6,321
Net income	$ 31,822	$ 7,675	$ 63,982	$ 9,255
Earnings per share:
Basic (in dollars per share)	$ 0.54	$ 0.14	$ 1.11	$ 0.17
Diluted (in dollars per share)	$ 0.52	$ 0.13	$ 1.06	$ 0.16
Weighted average common shares outstanding:
Basic (in shares)	59,108	55,541	57,769	55,508
Diluted (in shares)	60,990	58,729	60,578	58,829