Inventories - Schedule of Inventory Components (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Finished goods	$ 736	$ 538
Work-in-process	195	85
Bauxite and alumina	588	539
Purchased raw materials	798	619
Operating supplies	178	175
Inventories, total	$ 2,495	$ 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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