Basis of Presentation - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2023 Location Country
Basis Of Presentation [Line Items]
Number of countries in which entity operates | Country	9
Aluminum Segment [Member]
Basis Of Presentation [Line Items]
Ownership interest in joint venture	55.00%
Alcoa Corporation [Member]
Basis Of Presentation [Line Items]
Ownership interest in joint venture	25.10%
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%
Minimum [Member]
Basis Of Presentation [Line Items]
Number of operating locations | Location	27
Maximum [Member]
Basis Of Presentation [Line Items]
Percent of equity interest in other entity	50.00%