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No definition available.

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Debt instrument capitalization ratio.

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Debt instrument covenant interest coverage ratio.

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Extended maturity date of credit facility.

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Line of credit facility, unused borrowing capacity, cancelled amount.

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Percentage of cash restructuring charge in consolidated ebitda.

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Face (par) amount of debt instrument at time of issuance.

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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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The fair value of line of credit assumed in noncash investing or financing activities.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

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The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

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Debt (Credit Facility) - Additional Information (Detail) ¥ in Millions					12 Months Ended
	Jan. 01, 2025	Aug. 01, 2024 USD ($)	Jan. 17, 2024 USD ($)	Jan. 16, 2024	Dec. 31, 2024 USD ($)	Dec. 31, 2024 JPY (¥)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 JPY (¥)	Apr. 30, 2023 USD ($)	Jun. 27, 2022 USD ($)
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility										$ 1,250,000,000
Debt to capitalization ratio			60.00%
Principal amount of debt					$ 0		$ 0
Amounts borrowed under the credit facility					0		0
Revolving Credit Facility [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Percentage of cash restructuring charge in consolidated EBITDA	15.00%
Revolving Credit Facility [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Cash restructuring charges in consolidated EBITDA			$ 450,000,000
Revolving Credit Facility [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument covenant interest coverage ratio			300.00%	400.00%
Revolving Credit Facility [Member] \| Minimum [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument covenant interest coverage ratio	400.00%
$250 Japanese Yen Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility									$ 250,000,000
Principal amount of debt					0		0
Amounts borrowed under the credit facility					201,000,000	¥ 29,686	10,000,000	¥ 1,495
Amounts repaid under the credit facility					$ 196,000,000	¥ 29,686	$ 10,000,000	¥ 1,495
Alumina Limited Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit assumed		$ 385,000,000
Cancelled amount of outstanding lender tranche commitments		385,000,000
Alumina Limited Revolving Credit Facility [Member] \| Due in October 2025 [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility		$ 100,000,000
Extended Maturity Date of Credit Facility		2025-10
Alumina Limited Revolving Credit Facility [Member] \| Due in January 2026 [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility		$ 150,000,000
Extended Maturity Date of Credit Facility		2026-01
Alumina Limited Revolving Credit Facility [Member] \| Due in July 2026 [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility		$ 150,000,000
Extended Maturity Date of Credit Facility		2026-07
Cancelled undrawn portions of revolving credit facility		$ 15,000,000
Alumina Limited Revolving Credit Facility [Member] \| Due in June 2027 [Member]
Debt Instrument [Line Items]
Unsecured revolving credit facility		$ 100,000,000
Extended Maturity Date of Credit Facility		2027-06
Cancelled undrawn portions of revolving credit facility		$ 100,000,000