Other Financial Information - Schedule of Other Noncurrent Liabilities and Deferred Credits (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Other Financial Information [Abstract]
Noncurrent accrued tax liability	$ 174	$ 169
Accrued compensation and retirement costs	120	116
Operating lease obligations	64	82
Deferred carbon dioxide emission credits	54	56
Value-added tax credits payable to Arconic Corporation	47
Noncurrent restructuring reserve	44	1
Deferred alumina sales revenue	36	45
Noncurrent site separation reserve	26
Other	34	46
Other noncurrent liabilities and deferred credits, total	$ 599	$ 515