Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Income from continuing operations	$ 294	$ 689	$ 862	$ 1,110
Income from discontinued operations, net of income taxes	10,440	57	10,513	3,048
Net income	$ 10,734	$ 746	$ 11,375	$ 4,158
Denominator:
Weighted average shares of common stock - basic (in shares)	674	703	678	728
Dilutive effect of equity incentive awards (in shares)	11	8	11	6
Weighted average shares of common stock - diluted (in shares)	685	711	689	734
Income per share - basic:
Continuing operations (in usd per share)	$ 0.44	$ 0.98	$ 1.27	$ 1.53
Discontinued operations (in usd per share)	15.48	0.08	15.52	4.18
Net income per share - basic (in usd per share)	15.92	1.06	16.79	5.71
Income per share - diluted:
Continuing operations (in usd per share)	0.43	0.97	1.25	1.51
Discontinued operations (in usd per share)	15.25	0.08	15.27	4.16
Net income per share - diluted (in usd per share)	$ 15.68	$ 1.05	$ 16.52	$ 5.67
Common stock equivalents excluded from income per diluted share because their effect would have been anti-dilutive (in shares)	8	1	9	6