Investments (Tables)

6 Months Ended

Jun. 30, 2022

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):

Second quarter ended June 30, 2022	Saudi Arabia Joint Venture			Mining			Energy			Other
Sales	$	1,016		$	191		$	65		$	125
Cost of goods sold		712			123			23			115
Net income (loss)		156			32			29			(30	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		39			12			12			(15	)
Other		(4	)		(2	)		(2	)		19
Alcoa Corporation’s equity in net income of    affiliated companies		35			10			10			4
Second quarter ended June 30, 2021
Sales	$	741		$	197		$	60		$	96
Cost of goods sold		508			146			32			78
Net income (loss)		102			25			27			(4	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		26			9			11			(2	)
Other		—			(1	)		—			8
Alcoa Corporation’s equity in net income of    affiliated companies		26			8			11			6
Six months ended June 30, 2022
Sales	$	1,913		$	422		$	127		$	242
Cost of goods sold		1,328			269			53			222
Net income (loss)		311			81			52			(58	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		78			26			21			(28	)
Other		(4	)		(2	)		(1	)		15
Alcoa Corporation’s equity in net income (loss) of    affiliated companies		74			24			20			(13	)
Six months ended June 30, 2021
Sales	$	1,423		$	370		$	115		$	191
Cost of goods sold		1,011			269			57			171
Net income (loss)		147			20			52			(6	)
Equity in net income (loss) of affiliated companies,    before reconciling adjustments		37			10			21			(3	)
Other		(4	)		(1	)		—			11
Alcoa Corporation’s equity in net income of    affiliated companies		33			9			21			8