Inventories - Schedule of Inventory Components (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Finished goods	$ 490	$ 529
Work-in-process	324	257
Bauxite and alumina	571	376
Purchased raw materials	843	619
Operating supplies	172	175
Inventories, total	$ 2,400	$ 1,956

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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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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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of products used directly or indirectly in the manufacturing or production process, which may or may not become part of the final product. May also include items used in the storage, presentation or transportation of physical goods.

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