Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 67	$ 74
Materials and supplies	916	445
Commodity inventory and finished goods	665	788
Inventories, gross	1,648	1,307
Revaluation to LIFO	(47)	(47)
Total	$ 1,601	$ 1,260

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

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

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Amount before valuation and LIFO reserves of other supplies used within the manufacturing or production process expected to be consumed within one year or operating cycle, if longer.

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