Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Income from continuing operations	$ 621	$ 210	$ 1,761	$ 1,047
Income from discontinued operations, net of income taxes	43	100	3,061	183
Net income	$ 664	$ 310	$ 4,822	$ 1,230
Denominator:
Weighted average shares of common stock - basic (in shares)	696	830	717	863
Dilutive effect of equity incentive awards (in shares)	12	7	8	7
Weighted average shares of common stock - diluted (in shares)	708	837	725	870
Income per share - basic:
Continuing operations (in usd per share)	$ 0.89	$ 0.25	$ 2.46	$ 1.21
Discontinued operations (in usd per share)	0.06	0.12	4.26	0.22
Net income per share - basic (in usd per share)	0.95	0.37	6.72	1.43
Income per share - diluted:
Continuing operations (in usd per share)	0.88	0.25	2.43	1.20
Discontinued operations (in usd per share)	0.06	0.12	4.22	0.22
Net income per share - diluted (in usd per share)	$ 0.94	$ 0.37	$ 6.65	$ 1.42
Common stock equivalents excluded from income per diluted share because their effect would have been anti-dilutive (in shares)	0	6	1	19