Derivatives and Other Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Detail for Level 1 and 3 Derivatives

The following tables present the detail for Level 1 and 3 derivatives (see additional Level 3 information in further tables below):

	2023				2022
Balance at December 31,	Assets		Liabilities		Assets		Liabilities
Level 1 derivative instruments	$	16	$	9	$	84	$	14
Level 3 derivative instruments		16		1,297		52		1,212
Total	$	32	$	1,306	$	136	$	1,226
Less: Current		29		214		134		200
Noncurrent	$	3	$	1,092	$	2	$	1,026

	2023						2022
Year ended December 31,	Unrealized gain (loss) recognized in Other comprehensive loss			Realized gain (loss) reclassed from Other comprehensive loss to earnings			Unrealized gain (loss) recognized in Other comprehensive loss			Realized gain (loss) reclassed from Other comprehensive loss to earnings
Level 1 derivative instruments	$	31		$	86		$	116		$	35
Level 3 derivative instruments		(326	)		(221	)		(247	)		(345	)
Noncontrolling and equity interest (Level 2)		—			5			12			(6	)
Total	$	(295	)	$	(130	)	$	(119	)	$	(316	)

Schedule of Outstanding Quantities of Derivative Instruments

The following table presents the outstanding quantities of derivative instruments classified as Level 1:

	Classification	December 31, 2023		December 31, 2022
Aluminum (in kmt)	Commodity buy forwards		78		176
Aluminum (in kmt)	Commodity sell forwards		46		337
Foreign currency (in millions of euro)	Foreign exchange buy forwards		48		60
Foreign currency (in millions of euro)	Foreign exchange sell forwards		9		—
Foreign currency (in millions of Norwegian krone)	Foreign exchange buy forwards		138		302
Foreign currency (in millions of Brazilian real)	Foreign exchange buy forwards		467		1,008
Foreign currency (in millions of Brazilian real)	Foreign exchange sell forwards		—		7
Foreign currency (in millions of Canadian dollar)	Foreign exchange buy forwards		31		—

Schedule of Fair Values of Level 3 Derivative Instruments Outstanding

Level 3 derivative instruments outstanding as of December 31, 2023 are described in the table below:

Description	Designation	Contract Termination	Unobservable Inputs Impacting Valuation	Sensitivity to Inputs
Power contracts
Embedded derivative that indexes the price of power to the LME price of aluminum plus the Midwest premium	Cash flow hedge of forward sales of aluminum	March 2026 December 2029 February 2036	LME price, Midwest premium and MWh per year	Increase in LME price and/or the Midwest premium results in a higher cost of power and an increase to the derivative liability
Embedded derivative that indexes the price of power to the LME price of aluminum	Cash flow hedge of forward sales of aluminum	September 2027	LME price and MWh per year	Increase in LME price results in a higher cost of power and an increase to the derivative liability
Embedded derivative that indexes the price of power to the credit spread between the Company and the counterparty	Not designated	October 2028	Estimated credit spread	Wider credit spread results in a higher cost of power and increase in the derivative liability
Financial contracts
Hedge power prices	Not designated	June 2035	LME price and power price	Lower prices in the power market or higher LME prices result in an increase in the derivative liability

Schedule of Quantitative Information for Level 3 Derivative Contracts

The following table presents quantitative information related to the significant unobservable inputs described above for Level 3 derivative instruments (megawatt hours in MWh):

	December 31, 2023		Unobservable Input	Unobservable Input Range
Asset Derivatives
Financial contract (undesignated)	$	16	Interrelationship of forward energy price, LME forward price and the Consumer Price Index	Electricity (per MWh)	2024: $50.99 2024: $53.55
				LME (per mt)	2024: $2,352
					2024: $2,424
Total Asset Derivatives	$	16
Liability Derivatives
Power contract	$	197	MWh of energy needed to produce the forecasted mt of aluminum	LME (per mt)	2024: $2,352 2027: $2,796
				Electricity	Rate of 4 million MWh per year
Power contracts		1,100	MWh of energy needed to produce the forecasted mt of aluminum	LME (per mt)	2024: $2,352 2029: $2,904 2036: $3,153
				Midwest premium (per pound)	2024: $0.1880 2029: $0.2300 2036: $0.2300
				Electricity	Rate of 18 million MWh per year
Power contract		—	MWh of energy needed to produce the forecasted mt of aluminum	LME (per mt)	2024: $2,352 2024: $2,381
				Midwest premium (per pound)	2024: $0.1880 2024: $0.2140
				Electricity	Rate of 2 million MWh per year
Power contract (undesignated)		—	Estimated spread between the 30-year debt yield of Alcoa and the counterparty	Credit spread	1.15%: 30-year debt yield spread 6.33%: Alcoa (estimated) 5.18%: counterparty
Total Liability Derivatives	$	1,297

Schedule of Fair Values of Level 3 Derivative Instruments Recorded as Assets and Liabilities

The fair values of Level 3 derivative instruments recorded in the accompanying Consolidated Balance Sheet were as follows:

Asset Derivatives	December 31, 2023		December 31, 2022
Derivatives designated as hedging instruments:
Current—financial contract	$	—	$	20
Total derivatives designated as hedging instruments	$	—	$	20
Derivatives not designated as hedging instruments:
Current—financial contract	$	16	$	32
Total derivatives not designated as hedging instruments	$	16	$	32
Total Asset Derivatives	$	16	$	52
Liability Derivatives
Derivatives designated as hedging instruments:
Current—power contracts	$	210	$	195
Noncurrent—power contracts		1,087		1,017
Total derivatives designated as hedging instruments	$	1,297	$	1,212
Total Liability Derivatives	$	1,297	$	1,212

Schedule of Net Fair Values of Level 3 Derivative Instruments and Effect of Hypothetical Change (Increase or Decrease of 10%) in Market Prices or Rates

The following table shows the net fair values of the Level 3 derivative instruments at December 31, 2023 and the effect on these amounts of a hypothetical change (increase or decrease of 10%) in the market prices or rates that existed as of December 31, 2023:

	Fair value asset (liability)			Index change of + / -10%
Power contracts	$	(1,297	)	$	300
Embedded credit derivative		-			-
Financial contracts		16			8

Schedule of Reconciliation of Activity for Derivative Contracts

The following tables present a reconciliation of activity for Level 3 derivative instruments:

	Assets
2023	Power contracts			Financial contracts
January 1, 2023	$	—		$	52
Total gains or losses included in:
Sales (realized)		(4	)		—
Cost of goods sold (realized)		—			(20	)
Other expenses, net (unrealized/realized)		—			(5	)
Other comprehensive income (unrealized)		4			—
Settlements and other		—			(11	)
December 31, 2023	$	—		$	16
Change in unrealized gains or losses included in earnings    for derivative instruments held at December 31, 2023:
Other expenses, net	$	—		$	(5	)

	Liabilities
2023	Power contracts
January 1, 2023	$	1,212
Total gains or losses included in:
Sales (realized)		(245	)
Other comprehensive income (unrealized)		330
December 31, 2023	$	1,297

	Assets
2022	Financial contracts
January 1, 2022	$	2
Total gains or losses included in:
Sales (realized)		—
Other income, net (unrealized/realized)		171
Other comprehensive income (unrealized)		20
Settlements and other		(141	)
December 31, 2022	$	52
Change in unrealized gains or losses included in earnings    for derivative instruments held at December 31, 2022:
Other income, net	$	171

	Liabilities
2022	Power contracts			Embedded credit derivative
January 1, 2022	$	1,290		$	3
Total gains or losses included in:
Sales (realized)		(345	)		—
Other income, net (unrealized/realized)		—			(3	)
Other comprehensive (income) loss (unrealized)		267			—
December 31, 2022	$	1,212		$	—
Change in unrealized gains or losses included in earnings    for derivative instruments held at December 31, 2022:
Other income, net	$	—		$	(3	)

Schedule of Carrying Values and Fair Values of Other Financial Instruments

The carrying values and fair values of Alcoa Corporation’s other financial instruments were as follows:

	2023				2022
December 31,	Carrying value		Fair value		Carrying value		Fair value
Cash and cash equivalents	$	944	$	944	$	1,363	$	1,363
Restricted cash		103		103		111		111
Short-term borrowings		56		56		—		—
Long-term debt due within one year		79		79		1		1
Long-term debt, less amount due within one year		1,732		1,702		1,806		1,744