Consolidated Statements of Changes in Equity and Redeemable Non-Controlling Interest - USD ($) $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income/(Loss)	Non- Controlling Interest in Consolidated Subsidiaries	Cumulative Effect, Period Of Adoption, Adjustment	Cumulative Effect, Period Of Adoption, Adjustment Retained Earnings
Beginning Balance (in shares) at Dec. 31, 2018		604,000,000	35,000,000
Beginning Balance at Dec. 31, 2018	$ 17,231	$ 6	$ (2,354)	$ 11,547	$ 8,317	$ (315)	$ 30
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	6					6
Exercise of common stock options	17			17
Repurchases of common stock (in shares)			(10,000,000)
Repurchases of common stock	(780)		$ (780)
Payments relating to treasury shares	(60)		$ (60)
Stock-based compensation	73			73
Issuance under the employee stock purchase plan	14			14
Issuance of restricted stock (in shares)		2,000,000
Distributions of profits	(14)						(14)
Dividends paid to stockholders	(312)				(312)
Net income (loss) attributable to non-controlling interest	1				(14)		15
Net income	970				970
Ending Balance (in shares) at Jun. 30, 2019		606,000,000	45,000,000
Ending Balance at Jun. 30, 2019	17,146	$ 6	$ (3,194)	11,651	8,961	(309)	31
Redeemable non-controlling interest, Beginning balance at Dec. 31, 2018	71
Increase (Decrease) in Temporary Equity [Roll Forward]
Stock-based compensation	2
Net income (loss) attributable to non-controlling interest	(1)
Redeemable non-controlling interest, Ending balance at Jun. 30, 2019	72
Beginning Balance (in shares) at Dec. 31, 2018		604,000,000	35,000,000
Beginning Balance at Dec. 31, 2018	$ 17,231	$ 6	$ (2,354)	11,547	8,317	(315)	30
Ending Balance (in shares) at Dec. 31, 2019	607,000,000	607,000,000	53,000,000
Ending Balance at Dec. 31, 2019	$ 17,286	$ 6	$ (3,879)	11,742	9,629	(243)	31	$ (10)	$ (10)
Redeemable non-controlling interest, Beginning balance at Dec. 31, 2018	71
Redeemable non-controlling interest, Ending balance at Dec. 31, 2019	$ 78
Increase (Decrease) in Temporary Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Beginning Balance (in shares) at Mar. 31, 2019		606,000,000	41,000,000
Beginning Balance at Mar. 31, 2019	$ 17,130	$ 6	$ (2,851)	11,597	8,644	(290)	24
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	(19)					(19)
Exercise of common stock options	12			12
Repurchases of common stock (in shares)			(4,000,000)
Repurchases of common stock	(340)		$ (340)
Payments relating to treasury shares	(3)		$ (3)
Stock-based compensation	40			40
Issuance under the employee stock purchase plan	2			2
Dividends paid to stockholders	(155)				(155)
Net income (loss) attributable to non-controlling interest	1				(6)		7
Net income	478				478
Ending Balance (in shares) at Jun. 30, 2019		606,000,000	45,000,000
Ending Balance at Jun. 30, 2019	17,146	$ 6	$ (3,194)	11,651	8,961	(309)	31
Redeemable non-controlling interest, Beginning balance at Mar. 31, 2019	71
Increase (Decrease) in Temporary Equity [Roll Forward]
Stock-based compensation	2
Net income (loss) attributable to non-controlling interest	(1)
Redeemable non-controlling interest, Ending balance at Jun. 30, 2019	$ 72
Beginning Balance (in shares) at Dec. 31, 2019	607,000,000	607,000,000	53,000,000
Beginning Balance at Dec. 31, 2019	$ 17,286	$ 6	$ (3,879)	11,742	9,629	(243)	31	$ (10)	$ (10)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	(78)					(78)
Exercise of common stock options	22			22
Repurchases of common stock (in shares)			(12,000,000)
Repurchases of common stock	(1,099)		$ (1,099)
Payments relating to treasury shares	(72)		$ (72)
Stock-based compensation	73			73
Issuance under the employee stock purchase plan	16			16
Warrants issued to minority interest holders	3			3
Issuance of restricted stock (in shares)		2,000,000
Distributions of profits	(15)						(15)
Dividends paid to stockholders	(330)				(330)
Redeemable non-controlling interest	0
Issuance of non-controlling interest	9						9
Net income (loss) attributable to non-controlling interest	3				(13)		16
Net income	$ 1,186				1,186
Ending Balance (in shares) at Jun. 30, 2020	609,000,000	609,000,000	65,000,000
Ending Balance at Jun. 30, 2020	$ 16,994	$ 6	$ (5,050)	11,856	10,462	(321)	41
Redeemable non-controlling interest, Beginning balance at Dec. 31, 2019	78
Increase (Decrease) in Temporary Equity [Roll Forward]
Stock-based compensation	8
Warrants issued to minority interest holders	2
Redeemable non-controlling interest	10
Net income (loss) attributable to non-controlling interest	(3)
Redeemable non-controlling interest, Ending balance at Jun. 30, 2020	95
Beginning Balance (in shares) at Mar. 31, 2020		609,000,000	61,000,000
Beginning Balance at Mar. 31, 2020	16,965	$ 6	$ (4,647)	11,810	10,103	(333)	26
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	12					12
Exercise of common stock options	11			11
Repurchases of common stock (in shares)			(4,000,000)
Repurchases of common stock	(400)		$ (400)
Payments relating to treasury shares	(3)		$ (3)
Stock-based compensation	35			35
Dividends paid to stockholders	(164)				(164)
Issuance of non-controlling interest	9						9
Net income (loss) attributable to non-controlling interest	1				(5)		6
Net income	$ 528				528
Ending Balance (in shares) at Jun. 30, 2020	609,000,000	609,000,000	65,000,000
Ending Balance at Jun. 30, 2020	$ 16,994	$ 6	$ (5,050)	$ 11,856	$ 10,462	$ (321)	$ 41
Redeemable non-controlling interest, Beginning balance at Mar. 31, 2020	97
Increase (Decrease) in Temporary Equity [Roll Forward]
Stock-based compensation	(1)
Net income (loss) attributable to non-controlling interest	(1)
Redeemable non-controlling interest, Ending balance at Jun. 30, 2020	$ 95