Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2018		1,282,000,000
Beginning balance at Dec. 31, 2018	$ 21,534	$ 1	$ 2,282	$ 80	$ 19,024	$ 147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,675				2,690	(15)
Other comprehensive income (loss), net of tax	37			37
Issuances under employee stock purchase plan (in shares)		2,000,000
Issuances under employee stock purchase plan	90		90
Issuance under equity incentive plans (in shares)		8,000,000
Issuances under equity incentive plans	92		92
Stock-based compensation	479		479
Repurchases of common stock (in shares)		(26,000,000)
Repurchases of common stock	(1,748)		(73)		(1,675)
Dividends declared	(2,431)				(2,431)
Ending balance (in shares) at Sep. 30, 2019		1,266,000,000
Ending balance at Sep. 30, 2019	20,736	$ 1	2,870	117	17,616	132
Beginning balance (in shares) at Jun. 30, 2019		1,267,000,000
Beginning balance at Jun. 30, 2019	22,751	$ 1	2,684	102	19,829	135
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,168)				(1,165)	(3)
Other comprehensive income (loss), net of tax	15			15
Issuances under employee stock purchase plan (in shares)		1,000,000
Issuances under employee stock purchase plan	27		27
Issuance under equity incentive plans (in shares)		2,000,000
Issuances under equity incentive plans	10		10
Stock-based compensation	160		160
Repurchases of common stock (in shares)		(4,000,000)
Repurchases of common stock	(252)		(11)		(241)
Dividends declared	(807)				(807)
Ending balance (in shares) at Sep. 30, 2019		1,266,000,000
Ending balance at Sep. 30, 2019	$ 20,736	$ 1	2,870	117	17,616	132
Beginning balance (in shares) at Dec. 31, 2019	1,266,000,000	1,266,000,000
Beginning balance at Dec. 31, 2019	$ 22,650	$ 1	3,051	85	19,388	125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in noncontrolling interest (Note 6)	(72)					(72)
Net income (loss)	(1,455)				(1,428)	(27)
Other comprehensive income (loss), net of tax	(62)		1	(62)	(1)
Issuances under employee stock purchase plan (in shares)		2,000,000
Issuances under employee stock purchase plan	100		100
Issuance under equity incentive plans (in shares)		10,000,000
Issuances under equity incentive plans	148		148
Stock-based compensation	482		482
Repurchases of common stock (in shares)		(25,000,000)
Repurchases of common stock	(1,714)		(70)		(1,644)
Dividends declared	$ (2,599)				(2,599)
Ending balance (in shares) at Sep. 30, 2020	1,253,000,000	1,253,000,000
Ending balance at Sep. 30, 2020	$ 17,471	$ 1	3,712	23	13,709	26
Beginning balance (in shares) at Jun. 30, 2020		1,254,000,000
Beginning balance at Jun. 30, 2020	18,142	$ 1	3,511	70	14,445	115
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in noncontrolling interest (Note 6)	(82)					(82)
Net income (loss)	353				360	(7)
Other comprehensive income (loss), net of tax	(47)		1	(47)	(1)
Issuances under employee stock purchase plan (in shares)		1,000,000
Issuances under employee stock purchase plan	34		34
Issuance under equity incentive plans (in shares)		2,000,000
Issuances under equity incentive plans	2		2
Stock-based compensation	173		173
Repurchases of common stock (in shares)		(4,000,000)
Repurchases of common stock	(238)		(9)		(229)
Dividends declared	$ (866)				(866)
Ending balance (in shares) at Sep. 30, 2020	1,253,000,000	1,253,000,000
Ending balance at Sep. 30, 2020	$ 17,471	$ 1	$ 3,712	$ 23	$ 13,709	$ 26