Subsequent Events	6 Months Ended
Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	R. Subsequent Events On July 1, 2022, Alcoa curtailed one of the three operating smelting potlines (54 kmt) at its Warrick Operations site due to operational challenges stemming from labor shortages in the region. Beginning in July 2022, the Company reduced production by approximately 15% at the San Ciprián (Spain) refinery to mitigate the impact of high natural gas costs. On July 20, 2022, Alcoa Corporation’s Board of Directors approved an additional common stock repurchase program under which the Company may purchase shares of its outstanding common stock up to an aggregate transactional value of $500, depending on the Company’s continuing analysis of market, financial, and other factors. The prior authorization had $150 remaining for share repurchases at the end of the second quarter of 2022. The share repurchase programs may be suspended or discontinued at any time and do not have predetermined expiration dates.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI https://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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