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- Definition

Amount, after allowance, receivable from customers, clients, or other third-parties, and receivables classified as other due within one year or the normal operating cycle, if longer.

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- Definition

Amount of decrease in additional paid in capital (APIC) resulting from dividends legally declared (or paid) in excess of retained earnings balance.

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- Definition

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Investment in and Advances to Non-Consolidated Affiliates and Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Sep. 30, 2022	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Schedule of Equity Method Investments [Line Items]
Net sales			$ 17,149,000,000	$ 16,210,000,000	$ 18,486,000,000
Return of capital to our common shareholder	$ 100,000,000	$ 100,000,000	0	100,000,000	100,000,000
Parent Company
Schedule of Equity Method Investments [Line Items]
Net sales			1,000,000	1,000,000	$ 1,000,000
Accounts receivable, net	$ 2,000,000		$ 1,000,000	2,000,000
Alunorf
Schedule of Equity Method Investments [Line Items]
Ownership percentage			50.00%
Difference between carrying amount and underlying equity			$ 392,000,000
Ulsan Aluminum, Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership percentage			50.00%
Contributions to equity method investee			$ 21,000,000	$ 30,000,000
Difference between carrying amount and underlying equity			$ 41,000,000
AluInfra Services SA
Schedule of Equity Method Investments [Line Items]
Ownership percentage			50.00%