Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenues	$ 5,767,691	$ 4,520,992
Cost of revenues	3,599,701	2,870,614
Marketing	503,830	616,578
Technology and development	453,817	372,764
General and administrative	252,087	201,952
Operating income	958,256	459,084
Other income (expense):
Interest expense	(184,083)	(135,529)
Interest and other income (expense)	21,697	76,104
Income before income taxes	795,870	399,659
Provision for income taxes	86,803	55,607
Net income	$ 709,067	$ 344,052
Earnings per share:
Basic (in dollars per share)	$ 1.61	$ 0.79
Diluted (in dollars per share)	$ 1.57	$ 0.76
Weighted-average common shares outstanding:
Basic (in shares)	439,352	436,947
Diluted (in shares)	452,494	451,922