Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic
Income from continuing operations	$ 2,534	$ 115	$ 6,040	$ 5,222
Less: cumulative dividends on subsidiary preferred stock	(31)	(2)	(60)	(2)
Income from continuing operations attributable to common stockholders	2,503	113	5,980	5,220
Loss from discontinued operations, net of tax	0	3,096	70	3,935
Net income (loss) attributable to common stockholders	$ 2,503	$ (2,983)	$ 5,910	$ 1,285
Weighted-average common shares outstanding - basic (in shares)	1,412	1,445	1,410	1,483
Basic earnings per common share – continuing operations (in dollars per share)	$ 1.77	$ 0.08	$ 4.24	$ 3.52
Basic loss per common share – discontinued operations (in dollars per share)	0.00	2.14	0.05	2.65
Basic earnings (loss) per common share (in dollars per share)	$ 1.77	$ (2.06)	$ 4.19	$ 0.87
Diluted
Income from continuing operations attributable to common stockholders – diluted	$ 2,503	$ 113	$ 5,980	$ 5,220
Loss from discontinued operations, net of tax – diluted	0	3,096	70	3,935
Net income (loss) attributable to common stockholders – diluted	$ 2,503	$ (2,983)	$ 5,910	$ 1,285
Weighted-average common shares outstanding - basic (in shares)	1,412	1,445	1,410	1,483
Dilutive effect of warrants and awards under stock incentive plans (in shares)	19	27	21	24
Weighted-average common shares outstanding - diluted (in shares)	1,431	1,472	1,431	1,507
Diluted earnings per common share – continuing operations (in dollars per share)	$ 1.75	$ 0.08	$ 4.18	$ 3.46
Diluted loss per common share – discontinued operations (in dollars per share)	0.00	2.11	0.05	2.61
Diluted earnings (loss) per common share (in dollars per share)	$ 1.75	$ (2.03)	$ 4.13	$ 0.85
Potentially dilutive securities (in shares)	4	6	4	6

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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- Definition

Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation.

+ References

No definition available.