Earnings Per Share - Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net Earnings	$ 771	$ 856	$ 870	$ 834	$ 843	$ 894	$ 877	$ 695	$ 3,331	$ 3,309	$ 5,471
Dividend Equivalents on Restricted Stock									0	(1)	(1)
Net Earnings, Attributable to Common Shareholders									$ 3,331	$ 3,308	$ 5,470
Denominator:
Average Common Shares Outstanding (in shares)									796	857	911
Other Potentially Dilutive Common Shares (in shares)									2	4	3
Average Common Shares Outstanding, Assuming Dilution (in shares)									798	861	914
Earnings Per Share, Basic (in dollars per share)	$ 0.99	$ 1.08	$ 1.08	$ 1.02	$ 1.02	$ 1.05	$ 1.02	$ 0.78	$ 4.18	$ 3.86	$ 6.01
Net Earnings Per Share, Assuming Dilution (in dollars per share)	$ 0.99	$ 1.08	$ 1.08	$ 1.02	$ 1.01	$ 1.05	$ 1.01	$ 0.78	$ 4.17	$ 3.84	$ 5.99