Asset Retirement obligations.

No definition available.

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- Definition

Amount of asset retirement obligations incurred during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481850/410-20-50-1

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- Definition

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481850/410-20-50-1

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- Definition

The amount of asset retirement costs previously incurred and capitalized separately from the capitalized amount of the associated long-lived assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482274/932-235-50-13

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- Definition

Amount of asset retirement obligations (ARO) costs incurred (whether capitalized or charged to expense) during the period.

+ References

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Asset Retirement Obligations - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2023
Asset Retirement Obligations [Line Items]
Liabilities incurred		$ 9
Capitalized asset retirement cost		1	$ 8
Intalco Aluminum Smelter [Member]
Asset Retirement Obligations [Line Items]
Liabilities incurred				$ 36
Magnesium Smelter Facility in Addy [Member]
Asset Retirement Obligations [Line Items]
Liabilities incurred		15
Cost of Goods Sold [Member]
Asset Retirement Obligations [Line Items]
Additional asset retirement obligation liabilities incurred		$ 8	39
Bauxite Residue Areas [Member]
Asset Retirement Obligations [Line Items]
Liabilities incurred			$ 47
Spent Pot Lining Treatment and Disposal [Member]
Asset Retirement Obligations [Line Items]
Liabilities incurred	$ 4			4
Lake Charles Anode Facility [Member] \| Restructuring and Other Charges [Member]
Asset Retirement Obligations [Line Items]
Reversals of previously recorded liabilities	$ 2			$ 2