Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement [Abstract]
Revenues	$ 3,609,282	$ 3,204,577	$ 2,162,625
Cost of revenues	2,625,866	2,039,901	1,357,355
Marketing	484,729	402,638	293,839
Technology and development	329,008	259,033	163,329
General and administrative	119,687	126,937	64,461
Operating income	49,992	376,068	283,641
Other income (expense):
Interest expense	(19,986)	(20,025)	(19,629)
Interest and other income (expense)	474	3,479	3,684
Income before income taxes	30,480	359,522	267,696
Provision for income taxes	13,328	133,396	106,843
Net income	$ 17,152	$ 226,126	$ 160,853
Earnings per share:
Basic (in dollars per share)	$ 0.31	$ 4.28	$ 3.06
Diluted (in dollars per share)	$ 0.29	$ 4.16	$ 2.96
Weighted-average common shares outstanding:
Basic (in shares)	55,521	52,847	52,529
Diluted (in shares)	58,904	54,369	54,304