Statement of Consolidated Operations (unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Sales (E)	$ 2,904	$ 2,602	$ 8,409	$ 7,956
Cost of goods sold (exclusive of expenses below)	2,393	2,469	7,330	7,388
Selling, general administrative, and other expenses	66	56	195	162
Research and development expenses	16	9	40	25
Provision for depreciation, depletion, and amortization	159	163	483	469
Restructuring and other charges, net (D)	30	22	250	195
Interest expense	44	26	111	79
Other expenses, net (P)	12	85	49	145
Total costs and expenses	2,720	2,830	8,458	8,463
Consolidated income (loss) before income taxes	184	(228)	(49)	(507)
Provision for (benefit from) income taxes	86	(35)	129	39
Net income (loss)	98	(193)	(178)	(546)
Less: Net income (loss) attributable to noncontrolling interest	8	(25)	(36)	(45)
NET INCOME (LOSS) ATTRIBUTABLE TO ALCOA CORPORATION	$ 90	$ (168)	$ (142)	$ (501)
EARNINGS PER SHARE ATTRIBUTABLE TO ALCOA CORPORATION COMMON SHAREHOLDERS (F):
Basic	$ 0.39	$ (0.94)	$ (0.72)	$ (2.81)
Diluted	$ 0.38	$ (0.94)	$ (0.72)	$ (2.81)