Short-Term Debt - Sumamry (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Short term borrowings
Commercial paper	$ 4,654	$ 7,503
Notes payable to banks and others with originating terms of one year or less	228	28
Current maturities of long-term debt	5,054	4,999
Current maturities of long-term finance leases	18
Current maturities of long-term capital leases		18
Redeemable long term obligations - Long-term debt	3,078	3,078
Subtotal	13,032	15,626
Reclassified to long-term debt	(9,750)	(9,900)
Total short-term debt	$ 3,282	$ 5,726
Weighted-average interest rate	1.69%	2.43%
Unamortized discounts and debt issuance costs	$ 0	$ 1