Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenues	$ 1,738,355	$ 1,409,432	$ 4,956,178	$ 4,019,928
Cost of revenues	1,173,958	954,394	3,342,111	2,738,428
Marketing	208,102	145,654	599,919	403,515
Technology and development	171,762	120,953	469,929	346,445
General and administrative	110,892	78,024	298,287	193,938
Operating income	73,641	110,407	245,932	337,602
Other income (expense):
Interest expense	(35,333)	(13,486)	(97,287)	(36,866)
Interest and other income (expense)	3,930	616	(27,491)	3,117
Income before income taxes	42,238	97,537	121,154	303,853
Provision for income taxes	12,806	38,242	41,691	120,425
Net income	$ 29,432	$ 59,295	$ 79,463	$ 183,428
Earnings per share:
Basic (in dollars per share)	$ 0.07	$ 0.14	$ 0.19	$ 0.44
Diluted (in dollars per share)	$ 0.07	$ 0.14	$ 0.18	$ 0.42
Weighted-average common shares outstanding:
Basic (in shares)	426,869	421,194	425,289	419,972
Diluted (in shares)	437,606	432,742	435,849	431,683