Investments (Tables)

3 Months Ended

Mar. 31, 2024

Equity Method Investments and Joint Ventures [Abstract]

Summary of Unaudited Financial Information for Alcoa Corporation's Equity Investments

A summary of unaudited financial information for Alcoa Corporation’s equity investments is as follows (amounts represent 100% of investee financial information):

First quarter ended March 31, 2024	Saudi Arabia Joint Venture			Mining			Energy			Other
Sales	$	711		$	115		$	63		$	115
Cost of goods sold		599			103			25			105
Net (loss) income		(8	)		(5	)		31			(16	)
Equity in net (loss) income of affiliated companies,    before reconciling adjustments		(2	)		(2	)		12			(8	)
Other		(8	)		—			(1	)		(5	)
Alcoa Corporation’s equity in net (loss) income of    affiliated companies		(10	)		(2	)		11			(13	)
First quarter ended March 31, 2023
Sales	$	600		$	187		$	58		$	121
Cost of goods sold		682			103			27			113
Net (loss) income		(252	)		24			24			(16	)
Equity in net (loss) income of affiliated companies,    before reconciling adjustments		(63	)		11			9			(8	)
Other		(12	)		—			—			(7	)
Alcoa Corporation’s equity in net (loss) income of    affiliated companies		(75	)		11			9			(15	)