Debt, Description of short-term debt (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Description of short-term debt [Line Items]
Outstanding short-term borrowings	$ 616
Weighted average interest rate, short-term debt (in hundredths)	0.90%	3.30%
U.S. Receivables Facility [Member]
Description of short-term debt [Line Items]
Expiration date	July 2021
Maximum borrowing capacity	$ 900
Additional borrowing capacity, uncommitted loans	$ 300
Credit facility description of interest rate	We pay variable interest rates on our secured borrowings
Maximum allowed letters of credit	$ 200
Outstanding short-term borrowings	0
Outstanding letters of credit	0
Unused availability	646
Commercial paper [Member]
Description of short-term debt [Line Items]
Maximum borrowing capacity	2,500
Outstanding short-term borrowings	$ 455
Description of interest rate	Interest rates on the commercial paper outstanding at September 30, 2020 are based on the terms of the notes and range from 0.16% to 0.22%