Investments (Tables)

9 Months Ended

Sep. 30, 2023

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, 2023	Saudi Arabia Joint Venture			Mining			Energy			Other
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	)
Third quarter ended September 30, 2022
Sales	$	773		$	167		$	66		$	121
Cost of goods sold		692			101			38			110
Net (loss) income		(94	)		14			28			(19	)
Equity in net (loss) income of affiliated companies,    before reconciling adjustments		(24	)		7			11			(9	)
Other		(1	)		—			(3	)		1
Alcoa Corporation’s equity in net (loss) income of    affiliated companies		(25	)		7			8			(8	)
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	)
Nine months ended September 30, 2022
Sales	$	2,686		$	589		$	193		$	363
Cost of goods sold		2,020			370			91			332
Net income (loss)		217			95			80			(77	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		54			33			32			(37	)
Other		(5	)		(2	)		(4	)		16
Alcoa Corporation’s equity in net income (loss) of    affiliated companies		49			31			28			(21	)