Fair Value Measurements, Including Derivatives (Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - Fair value, recurring - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets
Total assets	$ 148
Liabilities
Total liabilities	19	$ 27
Commodity Contract
Assets
Total assets	148
Interest Rate Contract [Member]
Liabilities
Total liabilities	19	27
Level 1
Assets
Total assets	0
Liabilities
Total liabilities	0	0
Level 1 | Commodity Contract
Assets
Total assets	0
Level 1 | Interest Rate Contract [Member]
Liabilities
Total liabilities	0	0
Level 2
Assets
Total assets	0
Liabilities
Total liabilities	19	27
Level 2 | Commodity Contract
Assets
Total assets	0
Level 2 | Interest Rate Contract [Member]
Liabilities
Total liabilities	19	27
Level 3
Assets
Total assets	148
Liabilities
Total liabilities	0	0
Level 3 | Commodity Contract
Assets
Total assets	148
Level 3 | Interest Rate Contract [Member]
Liabilities
Total liabilities	$ 0	$ 0