Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Schedule of Inventories
Refinery feedstocks	$ 2,607	$ 2,427
Refined petroleum products and blendstocks	4,423	3,459
Ethanol feedstocks and products	211	242
Materials and supplies	260	256
Inventories	7,501	6,384
Inventories (Textual)
Excess of market value over carrying amount of LIFO inventories	4,700	3,000
Amount of non-LIFO inventory	$ 1,400	$ 1,000

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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The excess of replacement or current cost over the stated LIFO (last in first out) inventory value when the LIFO inventory method is utilized.

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Carrying amount as of the balance sheet date of finished goods inventories for petroleum products, crude oil, petrochemical products, and other oil and gas inventories.

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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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Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.

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The amount of weighted average cost inventory present at the reporting date when inventory is valued using different valuation methods.

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Carrying amount as of the balance sheet date of ethanol feedstocks and products.

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Inventories, Textual [Abstract]

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