Debt (Short Term Debt Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Short-term debt	$ 11,428,000,000	$ 11,747,000,000
Line of credit | Accounts receivable securitization facility expiring 2019
Short-term Debt [Line Items]
Short-term debt	929,000,000	$ 850,000,000
Line of credit facility, maximum borrowing capacity	$ 975,000,000
Extension period	364 days
Collateral amount	$ 1,046,000,000.000