Statement of Changes in Consolidated Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Non-controlling Interest [Member]
Balance at Dec. 31, 2020	$ 5,016	$ 2	$ 9,663	$ (725)	$ (5,629)	$ 1,705
Net income (loss)	570			429		141
Other comprehensive income (loss) (G)	998				1,037	(39)
Stock-based compensation (N)	39		39
Net effect of tax withholding for compensation plans and exercise of stock options (N)	25		25
Repurchase of common stock (N)	(150)		(150)
Dividends paid on Alcoa common stock ($0.10 per share) (N)	(19)			(19)
Contributions	21					21
Distributions	(215)					(215)
Other	(1)					(1)
Balance at Dec. 31, 2021	6,284	2	9,577	(315)	(4,592)	1,612
Net income (loss)	38			(123)		161
Other comprehensive income (loss) (G)	960				1,053	(93)
Stock-based compensation (N)	40		40
Net effect of tax withholding for compensation plans and exercise of stock options (N)	3		3
Repurchase of common stock (N)	(500)		(440)	(60)
Dividends paid on Alcoa common stock ($0.10 per share) (N)	(72)			(72)
Contributions	214					214
Distributions	(379)					(379)
Other	1		3			(2)
Balance at Dec. 31, 2022	6,589	2	9,183	(570)	(3,539)	1,513
Net income (loss)	(773)			(651)		(122)
Other comprehensive income (loss) (G)	(60)				(106)	46
Stock-based compensation (N)	35		35
Net effect of tax withholding for compensation plans and exercise of stock options (N)	(33)		(33)
Dividends paid on Alcoa common stock ($0.10 per share) (N)	(72)			(72)
Contributions	188					188
Distributions	(30)					(30)
Other	1		2			(1)
Balance at Dec. 31, 2023	$ 5,845	$ 2	$ 9,187	$ (1,293)	$ (3,645)	$ 1,594