Consolidated Balance Sheet (unaudited) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents (M)	$ 1,358	$ 944
Receivables from customers (I)	869	656
Other receivables	132	152
Inventories (J)	2,048	2,158
Fair value of derivative instruments (M)	22	29
Prepaid expenses and other current assets	452	466
Total current assets	4,881	4,405
Properties, plants, and equipment	19,959	20,381
Less: accumulated depreciation, depletion, and amortization	13,382	13,596
Properties, plants, and equipment, net	6,577	6,785
Investments (H)	969	979
Deferred income taxes	295	333
Fair value of derivative instruments (M)	1	3
Other noncurrent assets	1,605	1,650
Total assets	14,328	14,155
Current liabilities:
Accounts payable, trade	1,586	1,714
Accrued compensation and retirement costs	331	357
Taxes, including income taxes	94	88
Fair value of derivative instruments (M)	205	214
Other current liabilities	746	578
Long-term debt due within one year (K & M)	79	79
Total current liabilities	3,041	3,030
Long-term debt, less amount due within one year (K & M)	2,469	1,732
Accrued pension benefits (L)	267	278
Accrued other postretirement benefits (L)	437	443
Asset retirement obligations	718	772
Environmental remediation (O)	197	202
Fair value of derivative instruments (M)	925	1,092
Noncurrent income taxes	134	193
Other noncurrent liabilities and deferred credits	606	568
Total liabilities	8,794	8,310
CONTINGENCIES AND COMMITMENTS (Q)
Alcoa Corporation shareholders’ equity:
Common stock	2	2
Additional capital	9,184	9,187
Accumulated deficit	(1,564)	(1,293)
Accumulated other comprehensive loss (G)	(3,628)	(3,645)
Total Alcoa Corporation shareholders’ equity	3,994	4,251
Noncontrolling interest	1,540	1,594
Total equity	5,534	5,845		$ 6,589
Total liabilities and equity	$ 14,328	$ 14,155