v3.22.4

Contingencies and Commitments​ (Details)										1 Months Ended	3 Months Ended	8 Months Ended		12 Months Ended
	Mar. 31, 2022 claimant	Mar. 29, 2022 defendant claimant	Dec. 23, 2020 claimant defendant	Jun. 26, 2020 claimant	Jun. 12, 2020 police_officer claimant firefighter	Jun. 11, 2020 firefighter	Mar. 17, 2020 segment	Jun. 06, 2019 plaintiff	Sep. 15, 2017 executive	Jul. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Feb. 23, 2021 firefighter	Feb. 23, 2021 firefighter	Dec. 31, 2022 USD ($) claimant firefighter yr police_officer	Dec. 31, 2021 USD ($) police_officer	Dec. 31, 2020 USD ($)	Feb. 20, 2023 USD ($)	Jan. 01, 2023 USD ($)	Feb. 05, 2020 USD ($)	Aug. 31, 2012 USD ($)
Site Contingency [Line Items]
Environmental remediation											$ 85,000,000			$ 85,000,000	$ 64,000,000
Environmental remediation, current											40,000,000			40,000,000	15,000,000
Remediation reserve decrease														33,000,000	(5,000,000)	$ (2,000,000)
Accrual for Environmental Loss Contingencies, Revision in Estimates																5,000,000
Environmental remediation, additions														6,000,000
Environmental remediation, payments														11,000,000	84,000,000	82,000,000
Environmental remediation, increase for obligations transferred in connection with Separation																13,000,000
Environmental remediation, decrease for other items														1,000,000	3,000,000	3,000,000
Long-Term Purchase Commitment [Line Items]
Purchase commitments due in 2023											909,000,000			909,000,000
Purchase commitments due in 2024											106,000,000			106,000,000
Purchase commitments due in 2025											19,000,000			19,000,000
Purchase commitments due in 2026											15,000,000			15,000,000
Purchase commitments due in 2027											13,000,000			13,000,000
Purchase commitments due thereafter											24,000,000			24,000,000
Other Commitments [Line Items]
Debt instrument, face amount											700,000,000			700,000,000	$ 700,000,000				$ 1,200,000,000
Obligations to Perform Operations, Maintenance, and Monitoring at Environmental Remediation Sites
Site Contingency [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates											(9,000,000)
Behrens v. Arconic
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | plaintiff								247
Sullivan v. Arconic
Loss Contingencies [Line Items]
Number of former executives | executive									3
Aluminum Rolling Mill in Brazil
Site Contingency [Line Items]
Environmental remediation, additions																1,000,000
Aluminum Supply Contract | Subsequent events
Long-Term Purchase Commitment [Line Items]
Purchase commitments due in 2023																		$ 375,000,000
Purchase commitments due in 2024																		195,000,000
Purchase commitments due in 2025																		195,000,000
Unrecorded Unconditional Purchase Obligation																	$ 2,580,000,000	$ 765,000,000
Grenfell Tower Fire
Loss Contingencies [Line Items]
Loss Contingency Accrual, Provision														61,000,000
Loss Contingency, Receivable, Additions														$ 53,000,000
Grenfell Tower Fire | Grenfell Tower Fire, Survivors and Estates of Decedents
Loss Contingencies [Line Items]
Number of defendants | defendant		21	23
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Birnberg Peirce Ltd
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			113		4									106
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Howe & Co Solicitors
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant					2
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Russell-Cooke LLP
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant		1	33	3										34
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Deighton Pierce Glynn
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			7
Grenfell Tower Fire | GreSurvivors and Estates of Decedents, Represented by SMQ Legal Services
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			6											7
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Scott Moncrieff
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			3											4
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Saunders Law
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			27											31
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Imran Khan & Partners
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			40											47
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Howe & Co
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			61											57
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Hodge Jones and Allen Solicitor
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant		5	119											4
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Hickman & Rose
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			19											23
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Duncan Lewis Solicitors
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			10											12
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Bindmans LLP
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant	5		346
Grenfell Tower Fire | Survivors and Estates of Decedents, Represented by Bhatt Murphy Ltd
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			76											80
Grenfell Tower Fire | Emergency Responders, Represented by Thompsons Solicitors
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | firefighter						98								80
Number of additional plaintiffs added to suit | firefighter												10		7
Grenfell Tower Fire | Emergency Responders, Represented by Penningtons Manches Cooper LLP
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | police_officer					27									33	36
Grenfell Tower Fire | Emergency Responders, Represented by Pattinson and Brewer
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | firefighter					2
Number of claimants withdrawn from suit | firefighter													1
Grenfell Tower Fire | Grenfell Tower Fire, Survivors And Estates Of Decedents, Represented By Slater & Gordon
Loss Contingencies [Line Items]
Number of claimants/plaintiffs | claimant			26											27
Non-Compliance with Russian Federal Law No. 57-FZ | Federal Antimonopoly Services of the Russian Federation Litigation
Loss Contingencies [Line Items]
Loss Contingency, Number Of Subsidiaries | segment							2
Guarantee Obligations
Loss Contingencies [Line Items]
Guarantor obligations, carrying value											2,000,000			$ 2,000,000
Guarantee Obligations | Howmet Aerospace | Arconic Corporation
Loss Contingencies [Line Items]
Guarantor obligations, carrying value											0			0
Guarantee Obligations | Alcoa Corporation | Arconic Corporation
Loss Contingencies [Line Items]
Guarantor obligations, carrying value											8,000,000			8,000,000
Standby Letters of Credit
Loss Contingencies [Line Items]
Total amount committed under letters of credit											11,000,000			11,000,000
Standby Letters of Credit | Howmet Aerospace | Arconic Corporation
Loss Contingencies [Line Items]
Total amount committed under letters of credit											27,000,000			27,000,000
Standby Letters of Credit | Alcoa Corporation | Arconic Corporation
Loss Contingencies [Line Items]
Total amount committed under letters of credit											0			0
Surety Bonds
Loss Contingencies [Line Items]
Total amount committed under surety bonds											48,000,000			48,000,000
Surety Bonds | Howmet Aerospace | Arconic Corporation
Loss Contingencies [Line Items]
Total amount committed under surety bonds											4,000,000			4,000,000
Surety Bonds | Alcoa Corporation | Arconic Corporation
Loss Contingencies [Line Items]
Total amount committed under surety bonds											2,000,000			2,000,000
Active Remediation Systems and/or Monitoring and Inspection Programs at Several Sites
Site Contingency [Line Items]
Environmental remediation, additions																$ 2,000,000
Environmental remediation, decrease for other items														14,000,000	$ 4,000,000
Massena West, NY
Site Contingency [Line Items]
Environmental remediation											38,000,000			38,000,000	30,000,000
Accrual for Environmental Loss Contingencies, Revision in Estimates														(11,000,000)	(11,000,000)
Massena West, NY | Legal Matters, Other
Site Contingency [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates															$ (2,000,000)
Massena West, NY | Environmental Issue [Member]
Site Contingency [Line Items]
Environmental remediation, additions														13,000,000
Massena West, NY | Environmental Issue [Member] | Scenario, Plan
Site Contingency [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates										$ (22,000,000)
Lafayette, Indiana
Site Contingency [Line Items]
Remediation reserve decrease														$ 5,000,000
Accrual for Environmental Loss Contingencies, Years for Completion | yr														2
Fusina, Italy
Site Contingency [Line Items]
Remediation reserve decrease														$ 1,000,000
Environmental remediation, payments														1,000,000
Davenport, IA
Site Contingency [Line Items]
Environmental remediation, additions														500,000
Davenport, IA | Minimum
Site Contingency [Line Items]
Estimated Future Capital Expenditures											25,000,000			25,000,000
Davenport, IA | Maximum
Site Contingency [Line Items]
Estimated Future Capital Expenditures											$ 30,000,000			$ 30,000,000
Midwestern Disaster Area Revenue Bonds Series 2012 | Bonds
Other Commitments [Line Items]
Debt instrument, face amount																				$ 250,000,000

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