Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2024
Aluminum Segment [Member]
Basis Of Presentation [Line Items]
Ownership interest in joint venture	55.00%
AWAC [Member] | Alumina Limited [Member]
Basis Of Presentation [Line Items]
Non-controlling interest, ownership percentage	40.00%
AWAC [Member] | Alcoa Corporation [Member]
Basis Of Presentation [Line Items]
Ownership interest percentage	60.00%