Statement of Consolidated Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
NET (LOSS) INCOME ATTRIBUTABLE TO ALCOA CORPORATION	$ (231)	$ 469
Net income, Noncontrolling interest	(1)	84
Net (loss) income	(232)	553
Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits, Alcoa Corporation	4	22
Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits, Noncontrolling interest		1
Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits	4	23
Foreign currency translation adjustments, Alcoa Corporation	2	326
Foreign currency translation adjustments, Noncontrolling interest	15	98
Foreign currency translation adjustments	17	424
Net change in unrecognized gains/losses on cash flow hedges, Alcoa Corporation	(122)	(830)
Net change in unrecognized gains/losses on cash flow hedges, Noncontrolling interest		1
Net change in unrecognized gains/losses on cash flow hedges	(122)	(829)
Total Other comprehensive (loss) income, net of tax, Alcoa Corporation	(116)	(482)
Total Other comprehensive (loss) income, net of tax, Noncontrolling interest	15	100
Total Other comprehensive (loss) income, net of tax	(101)	(382)
Comprehensive (loss) income, Alcoa Corporation	(347)	(13)
Comprehensive (loss) income, Noncontrolling interest	14	184
Comprehensive (loss) income	$ (333)	$ 171