Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenues	$ 5,244,905	$ 3,999,374	$ 14,689,013	$ 11,607,500
Cost of revenues	3,097,919	2,531,128	8,974,190	7,234,138
Marketing	553,797	510,330	1,773,525	1,639,114
Technology and development	379,776	308,620	1,135,773	890,025
General and administrative	233,174	168,628	659,783	454,764
Operating income	980,239	480,668	2,145,742	1,389,459
Other income (expense):
Interest expense	(160,660)	(108,862)	(448,222)	(291,686)
Interest and other income (expense)	192,744	7,004	215,378	9,289
Income before income taxes	1,012,323	378,810	1,912,898	1,107,062
Provision for (benefit from) income taxes	347,079	(24,025)	632,952	29,754
Net income	$ 665,244	$ 402,835	$ 1,279,946	$ 1,077,308
Earnings per share:
Basic (in dollars per share)	$ 1.52	$ 0.92	$ 2.93	$ 2.48
Diluted (in dollars per share)	$ 1.47	$ 0.89	$ 2.83	$ 2.39
Weighted-average common shares outstanding:
Basic (in shares)	438,090	435,809	437,547	435,033
Diluted (in shares)	451,552	451,919	451,896	451,283