Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions		Total	February 2020 Public Offering [Member]	Redeemable Noncontrolling Interests [Member]	Common Stock [Member]		Common Stock [Member] February 2020 Public Offering [Member]		Additional Paid-In Capital [Member]		Additional Paid-In Capital [Member] February 2020 Public Offering [Member]	[1]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Total Stockholder's Equity [Member]	Total Stockholder's Equity [Member] February 2020 Public Offering [Member]	Noncontrolling Interests in Subsidiaries [Member]
Redeemable Noncontrolling Interests, Balance at Dec. 31, 2019				$ 643
Balance at Dec. 31, 2019		$ 7,467			$ 1	[1]			$ 12,736	[1]			$ (6,083)	$ (36)	$ 6,618		$ 849
Balance (Accounting Standards Update 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		(44)							(44)	[1]					(44)
Exercises of conversion feature of convertible senior notes		65			$ 0	[1]			65	[1]					65
Exercises of conversion feature of convertible senior notes, Shares	[1]				1
Issuance of common stock for equity incentive awards		217			$ 0	[1]			217	[1]					217
Issuance of common stock for equity incentive awards, Shares	[1]				11
Issuance of common stock public offering			$ 2,309				$ 0	[1]			$ 2,309					$ 2,309
Issuance of common stock public offering, shares	[1]						15
Stock-based compensation		611							611	[1]					611
Contributions from noncontrolling interests		17		2													17
Distributions to noncontrolling interests		(77)		(27)													(77)
Other				(2)
Net (loss) income		200		(3)									120		120		80
Other comprehensive income (loss)		(4)												(4)	(4)
Redeemable Noncontrolling Interests, Balance at Jun. 30, 2020				613
Balance at Jun. 30, 2020		10,724			$ 1	[1]			15,894	[1]			(6,000)	(40)	9,855		869
Balance, shares at Jun. 30, 2020	[1]				932
Redeemable Noncontrolling Interests, Balance at Mar. 31, 2020				632
Balance at Mar. 31, 2020		10,040			$ 1	[1]			15,389	[1]			(6,104)	(113)	9,173		867
Balance, shares at Mar. 31, 2020	[1]				927
Reclassification between equity and mezzanine equity for convertible senior notes		16							16	[1]					16
Exercises of conversion feature of convertible senior notes		65			$ 0	[1]			65	[1]					65
Exercises of conversion feature of convertible senior notes, Shares	[1]				1
Issuance of common stock for equity incentive awards		57			$ 0	[1]			57	[1]					57
Issuance of common stock for equity incentive awards, Shares	[1]				4
Stock-based compensation		367							367	[1]					367
Distributions to noncontrolling interests		(27)		(13)													(27)
Other				(2)
Net (loss) income		133		(4)									104		104		29
Other comprehensive income (loss)		73												73	73
Redeemable Noncontrolling Interests, Balance at Jun. 30, 2020				613
Balance at Jun. 30, 2020		10,724			$ 1	[1]			15,894	[1]			(6,000)	(40)	9,855		869
Balance, shares at Jun. 30, 2020	[1]				932
Redeemable Noncontrolling Interests, Balance at Dec. 31, 2020		604		604
Balance at Dec. 31, 2020		23,075			$ 1				27,260				(5,399)	363	22,225		850
Balance (Accounting Standards Update 2020-06 [Member]) at Dec. 31, 2020		263													263
Balance, shares at Dec. 31, 2020					960
Exercises of conversion feature of convertible senior notes		5			$ 0				5						5
Exercises of conversion feature of convertible senior notes, Shares					1
Settlements of warrants		0			$ 0										0
Settlement of warrants, shares					17
Issuance of common stock for equity incentive awards		252			$ 0				252						252
Issuance of common stock for equity incentive awards, Shares					6
Stock-based compensation		1,162							1,162						1,162
Contributions from noncontrolling interests		0		2													0
Distributions to noncontrolling interests		(46)		(26)													(46)
Net (loss) income		1,617		25									1,580		1,580		37
Other comprehensive income (loss)		(157)												(157)	157
Redeemable Noncontrolling Interests, Balance at Jun. 30, 2021		605		605
Balance at Jun. 30, 2021		25,645			$ 1				28,205				(3,608)	206	24,804		841
Balance (Accounting Standards Update 2020-06 [Member]) at Jun. 30, 2021									474				211
Balance, shares at Jun. 30, 2021					984
Redeemable Noncontrolling Interests, Balance at Mar. 31, 2021				601
Balance at Mar. 31, 2021		23,864			$ 1				27,623	[1]			(4,750)	143	23,017		847
Balance, shares at Mar. 31, 2021					963
Exercises of conversion feature of convertible senior notes		(6)			$ 0				(6)						6
Exercises of conversion feature of convertible senior notes, Shares					1
Settlements of warrants		0			$ 0										0
Settlement of warrants, shares					17
Issuance of common stock for equity incentive awards		69			$ 0				69						69
Issuance of common stock for equity incentive awards, Shares					3
Stock-based compensation		519							519						519
Contributions from noncontrolling interests		0		2													0
Distributions to noncontrolling interests		(26)		(14)													(26)
Net (loss) income		1,162		16									1,142		1,142		20
Other comprehensive income (loss)		63												63	63
Redeemable Noncontrolling Interests, Balance at Jun. 30, 2021		605		$ 605
Balance at Jun. 30, 2021		$ 25,645			$ 1				28,205				(3,608)	$ 206	$ 24,804		$ 841
Balance (Accounting Standards Update 2020-06 [Member]) at Jun. 30, 2021									$ 474				$ 211
Balance, shares at Jun. 30, 2021					984

[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.