Inventories - Schedule of Inventory Components (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Finished goods	$ 355	$ 385
Work-in-process	287	350
Bauxite and alumina	586	584
Purchased raw materials	700	923
Operating supplies	230	185
Inventories, total	$ 2,158	$ 2,427

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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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