Earnings Per Share - Computation of Basic Earnings Per Share, Assuming Dilution (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
Numerator:
Net Earnings	$ 894	$ 459	$ 2,466	$ 1,331
Dividend Equivalents on Restricted Stock	0	0	0	(1)
Net Earnings, Attributable to Common Shareholders	$ 894	$ 459	$ 2,466	$ 1,330
Denominator:
Average Common Shares Outstanding (in shares)	850	902	866	916
Other Potentially Dilutive Common Shares (in shares)	4	4	4	3
Average Common Shares Outstanding, Assuming Dilution (in shares)	854	906	870	919
Net Earnings Per Share, Basic (in dollars per share)	$ 1.05	$ 0.51	$ 2.85	$ 1.45
Net Earnings Per Share, Assuming Dilution (in dollars per share)	$ 1.05	$ 0.51	$ 2.83	$ 1.45