v3.25.2

Earnings Per Share - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2025	Jun. 30, 2024
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Undistributed earnings	$ 1		$ 10
Preferred stock dividends paid	$ 1	$ 0	$ 1
Stock Awards and Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares equivalents that would have been included in diluted average shares outstanding				2
Number of anti-dilutive securities				3

Shares that would have been included in diluted earnings per share calculation.

+ References

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- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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-Section 50
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-Publisher FASB
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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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- Definition

Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

+ References

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-Topic 505
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- Definition

Amount of undistributed earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 480
-SubTopic 10
-Name Accounting Standards Codification
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Alcoa Corp 10-Q