Statement of Consolidated Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Sales (E)	$ 11,895	$ 10,551	$ 12,451
Cost of goods sold (exclusive of expenses below)	10,044	9,813	10,212
Selling, general administrative, and other expenses	275	226	204
Research and development expenses	57	39	32
Provision for depreciation, depletion, and amortization	642	632	617
Restructuring and other charges, net (D)	341	184	696
Interest expense (U)	156	107	106
Other expenses (income), net (U)	91	134	(118)
Total costs and expenses	11,606	11,135	11,749
Income (Loss) before income taxes	289	(584)	702
Provision for income taxes (Q)	265	189	664
Net income (loss)	24	(773)	38
Less: Net (loss) income attributable to noncontrolling interest	(36)	(122)	161
Net income (loss) attributable to Alcoa Corporation	$ 60	$ (651)	$ (123)
Earnings per share attributable to Alcoa Corporation common shareholders (F):
Basic	$ 0.26	$ (3.65)	$ (0.68)
Diluted	$ 0.26	$ (3.65)	$ (0.68)