Investments (Tables)

3 Months Ended

Mar. 31, 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):

First quarter ended March 31, 2023	Saudi Arabia Joint Venture			Mining		Energy		Other
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	)
First quarter ended March 31, 2022
Sales	$	897		$	231	$	62	$	117
Cost of goods sold		616			146		30		107
Net income (loss)		155			49		23		(28	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		39			14		9		(13	)
Other		—			—		1		(4	)
Alcoa Corporation’s equity in net income (loss) of    affiliated companies		39			14		10		(17	)