Debt (Schedule of Short-term Debt) (Details) - USD ($) $ in Millions		Sep. 30, 2021	Dec. 31, 2020
Short-Term Borrowings and Current Installments of Long-Term Debt - Third Party and Affiliates
Current installments of long-term debt		$ 28	$ 431
Short-term borrowings, including amounts due to affiliates	[1]	75	65
Total		$ 103	$ 496
Weighted average interest rate, short-term borrowings		0.20%	0.60%

[1] The weighted average interest rate was 0.2% and 0.6% as of September 30, 2021 and December 31, 2020, respectively.