Debt (Schedule of Short-term Debt) (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Short-Term Borrowings and Current Installments of Long-Term Debt - Third Party and Affiliates
Current installments of long-term debt		$ 363	$ 367
Short-term borrowings, including amounts due to affiliates	[1]	56	77
Total		$ 743	$ 561
Weighted average interest rate, short-term borrowings		3.00%	3.20%
Revolving Credit Facility [Member]
Short-Term Borrowings and Current Installments of Long-Term Debt - Third Party and Affiliates
Weighted average interest rate, short-term borrowings		1.50%	6.00%
Accounts Receivable Securitization Facility [Member]
Short-Term Borrowings and Current Installments of Long-Term Debt - Third Party and Affiliates
Borrowings outstanding	[2]	$ 77	$ 77
Weighted average interest rate, short-term borrowings		3.40%	3.10%
Revolving Credit Facility [Member]
Short-Term Borrowings and Current Installments of Long-Term Debt - Third Party and Affiliates
Borrowings outstanding	[3]	$ 247	$ 40

[1] The weighted average interest rate was 3.0% and 3.2% as of March 31, 2019 and December 31, 2018, respectively.

[2] The weighted average interest rate was 3.4% and 3.1% as of March 31, 2019 and December 31, 2018, respectively.

[3] The weighted average interest rate was 1.5% and 6.0% as of March 31, 2019 and December 31, 2018, respectively.