Investments (Tables)

9 Months Ended

Sep. 30, 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):

Third quarter ended September 30, 2024	Saudi Arabia Joint Venture			Mining		Energy			Other
Sales	$	838		$	146	$	61		$	116
Cost of goods sold		696			113		27			104
Net (loss) income		(5	)		7		28			(19	)
Equity in net (loss) income of affiliated companies,    before reconciling adjustments		(2	)		3		12			(9	)
Other		(4	)		—		—			1
Alcoa Corporation’s equity in net (loss) income of    affiliated companies		(6	)		3		12			(8	)
Third quarter ended September 30, 2023
Sales	$	725		$	157	$	61		$	117
Cost of goods sold		645			121		28			105
Net (loss) income		(39	)		6		31			(21	)
Equity in net (loss) income of affiliated companies,    before reconciling adjustments		(10	)		3		12			(11	)
Other		(15	)		—		(2	)		(6	)
Alcoa Corporation’s equity in net (loss) income of    affiliated companies		(25	)		3		10			(17	)
Nine months ended September 30, 2024
Sales	$	2,353		$	419	$	183		$	345
Cost of goods sold		1,908			320		77			313
Net income (loss)		89			16		88			(55	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		22			7		35			(26	)
Other		(16	)		—		(1	)		8
Alcoa Corporation’s equity in net income (loss) of    affiliated companies		6			7		34			(18	)
Nine months ended September 30, 2023
Sales	$	2,025		$	516	$	178		$	354
Cost of goods sold		1,947			325		87			324
Net (loss) income		(390	)		44		77			(70	)
Equity in net (loss) income of affiliated companies,    before reconciling adjustments		(98	)		20		30			(34	)
Other		(30	)		1		(1	)		(6	)
Alcoa Corporation’s equity in net (loss) income of    affiliated companies		(128	)		21		29			(40	)