Summary Of Significant Accounting Policies (Schedule of Inventory) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Materials and supplies inventories	$ 75	$ 75
Commodities	149	130
Inventories	224	205
Net materials and supplies inventories reserves	$ 1	$ 2

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The aggregate carrying amount as of the balance sheet date of unrefined petroleum and the liquid hydrocarbon components recovered from natural gas.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Aggregated amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed. This amount is net of valuation reserves and adjustments.

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Amount of valuation reserve for inventory.

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