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, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019		Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net Earnings	$ 736	$ 499	$ 770	$ 856	[1]	$ 870	$ 834	$ 2,005	$ 2,560	[1]
Denominator:
Average Common Shares Outstanding (in shares)	765			790	[1]			767	803	[1]
Other Potentially Dilutive Common Shares (in shares)	2			2				2	2
Average Common Shares Outstanding, Assuming Dilution (in shares)	767			792	[1]			769	805	[1]
Net Earnings Per Share, Basic (in dollars per share)	$ 0.96			$ 1.08	[1]			$ 2.61	$ 3.19	[1]
Net Earnings Per Share, Assuming Dilution (in dollars per share)	$ 0.96			$ 1.08	[1]			$ 2.61	$ 3.18	[1]

[1] Certain prior year data has been reclassified to conform to the current presentation.