Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Equity - USD ($) shares in Millions, $ in Millions		Total	2.00% Convertible Senior Notes due in 2024 [Member]	May 2019 Public Offering [Member]	Redeemable Noncontrolling Interests [Member]	Common Stock [Member]		Common Stock [Member] May 2019 Public Offering [Member]		Additional Paid-In Capital [Member]	[1]	Additional Paid-In Capital [Member] 2.00% Convertible Senior Notes due in 2024 [Member]	[1]	Additional Paid-In Capital [Member] May 2019 Public Offering [Member]	[1]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Stockholder's Equity [Member]	Total Stockholder's Equity [Member] 2.00% Convertible Senior Notes due in 2024 [Member]	Total Stockholder's Equity [Member] May 2019 Public Offering [Member]	Noncontrolling Interests in Subsidiaries [Member]
Balance at Dec. 31, 2017		$ 5,234			$ 398	$ 1	[1]			$ 9,177						$ (4,974)	$ 33	$ 4,237			$ 997
Balance (Accounting Standards Update No. 2014-09 [Member]) at Dec. 31, 2017		534			8											623		623			(89)
Balance (Accounting Standards Update No. 2017-05 [Member]) at Dec. 31, 2017		9														9		9
Balance, shares at Dec. 31, 2017	[1]					844
Exercises of conversion feature of convertible senior notes		0				$ 0	[1]			0								0
Exercises of conversion feature of convertible senior notes, Shares	[1]					1
Issuance of common stock for equity incentive awards		296				$ 0	[1]			296								296
Issuance of common stock for equity incentive awards, Shares	[1]					18
Stock-based compensation		775								775								775
Contributions from noncontrolling interests		161			276																161
Distributions to noncontrolling interests		(210)			(61)																(210)
Other					(3)
Net income (loss)		(1,001)			(62)											(976)		(976)			(25)
Other comprehensive income (loss)		(41)															(41)	(41)
Balance at Dec. 31, 2018		5,757			556	$ 1	[1]			10,248						(5,318)	(8)	4,923			834
Balance (Accounting Standards Update No. 2016-02 [Member]) at Dec. 31, 2018		97														97		97
Balance, shares at Dec. 31, 2018	[1]					863
Conversion feature of Convertible Senior Notes			$ 491									$ 491							$ 491
Purchase of convertible note hedges		(476)								(476)								(476)
Sales of warrants		174								174								174
Issuance of common stock for equity incentive awards and acquisitions, net of transaction costs		482				$ 0	[1]			482								482
Issuance of common stock upon acquisition and equity incentive awards, net of transaction costs, Shares	[1]					24
Issuance of common stock public offering				$ 848				$ 0	[1]					$ 848						$ 848
Issuance of common stock public offering, shares	[1]							18
Stock-based compensation		973								973								973
Contributions from noncontrolling interests		174			105																174
Distributions to noncontrolling interests		(198)			(65)																(198)
Other		(4)			(1)					(4)								(4)
Net income (loss)		(823)			48											(862)		(862)			39
Other comprehensive income (loss)		(28)															(28)	(28)
Balance at Dec. 31, 2019		7,467			643	$ 1	[1]			12,736						(6,083)	(36)	6,618			849
Balance (Accounting Standards Update No. 2016-13 [Member]) at Dec. 31, 2019		(37)														(37)		(37)
Balance, shares at Dec. 31, 2019	[1]					905
Reclassification between equity and mezzanine equity for convertible senior notes		(51)								(51)								(51)
Exercises of conversion feature of convertible senior notes		59				$ 0	[1]			59								59
Exercises of conversion feature of convertible senior notes, Shares	[1]					2
Issuance of common stock for equity incentive awards		417				$ 0	[1]			417								417
Issuance of common stock for equity incentive awards, Shares	[1]					19
Issuance of common stock public offering		12,269				$ 0	[1]			12,269								12,269
Issuance of common stock public offering, shares	[1]					34
Stock-based compensation		1,861								1,861								1,861
Contributions from noncontrolling interests		17			7																17
Distributions to noncontrolling interests		(132)			(67)																(132)
Buy-outs of noncontrolling interests		(31)			(4)					(31)								(31)
Net income (loss)		837			25											721		721			116
Other comprehensive income (loss)		399															399	399
Balance at Dec. 31, 2020		$ 23,075			$ 604	$ 1	[1]			$ 27,260						$ (5,399)	$ 363	$ 22,225			$ 850
Balance, shares at Dec. 31, 2020	[1]					960

[1] Prior period results have been adjusted to reflect the five-for-one stock split effected in the form of a stock dividend in August 2020. See Note 1, Overview, for details regarding stock split and public offerings.