v3.22.0.1
Cover Page - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2021
Feb. 17, 2022
Jun. 30, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 1-39162    
Entity Registrant Name ARCONIC CORPORATION    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 84-2745636    
Entity Address, Address Line One 201 Isabella Street    
Entity Address, City or Town Pittsburgh    
Entity Address, State or Province PA    
Entity Address, Postal Zip Code 15212-5872    
City Area Code 412    
Local Phone Number 992-2500    
Title of 12(b) Security Common Stock, par value $0.01 per share    
Trading Symbol ARNC    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 3.9
Entity Common Stock, Shares Outstanding   105,024,907  
Documents Incorporated by Reference [Text Block] Part III of this Form 10-K incorporates by reference certain information from the registrant’s definitive Proxy Statement for its 2022 Annual Meeting of Stockholders to be filed pursuant to Regulation 14A (2022 Proxy Statement).    
Entity Central Index Key 0001790982    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Filer Category Large Accelerated Filer