Statement of Changes in Consolidated Equity (unaudited) - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Capital [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]	Non-controlling Interest [Member]
Balance at Dec. 31, 2020	$ 5,016	$ 2	$ 9,663	$ (725)	$ (5,629)	$ 1,705
Net income	219			175		44
Total Other comprehensive (loss) income, net of tax	(311)				(249)	(62)
Stock-based compensation	8		8
Common stock issued: compensation plans	4		4
Distributions	(62)					(62)
Other	(1)		(1)
Balance at Mar. 31, 2021	4,873	2	9,674	(550)	(5,878)	1,625
Balance at Dec. 31, 2021	6,284	2	9,577	(315)	(4,592)	1,612
Net income	553			469		84
Total Other comprehensive (loss) income, net of tax	(382)				(482)	100
Stock-based compensation	9		9
Common stock issued: compensation plans	2		2
Repurchase of common stock	(75)		(54)	(21)
Dividends paid on Alcoa common stock	(19)			(19)
Contributions	46					46
Distributions	(162)					(162)
Other	1		3			(2)
Balance at Mar. 31, 2022	$ 6,257	$ 2	$ 9,537	$ 114	$ (5,074)	$ 1,678