Statement of Changes in Consolidated Equity (Parenthetical) - $ / shares |
12 Months Ended | ||
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Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
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| Statement of Stockholders' Equity [Abstract] | |||
| Common stock dividends per share | $ 0.1 | $ 0.1 | $ 0.1 |
Pay vs Performance Disclosure - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
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| Pay vs Performance Disclosure | |||
| Net Income (Loss) | $ (651) | $ (123) | $ 429 |
Insider Trading Arrangements |
12 Months Ended |
|---|---|
Dec. 31, 2023 | |
| Trading Arrangements, by Individual | |
| Rule 10b5-1 Arrangement Adopted | false |
| Non-Rule 10b5-1 Arrangement Adopted | false |
| Rule 10b5-1 Arrangement Terminated | false |
| Non-Rule 10b5-1 Arrangement Terminated | false |
Basis of Presentation |
12 Months Ended |
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Dec. 31, 2023 | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
| Basis of Presentation | A. Basis of Presentation Alcoa Corporation (or the Company) is a vertically integrated aluminum company comprised of bauxite mining, alumina refining, aluminum production (smelting and casting), and energy generation. Through direct and indirect ownership, the Company has 27 operating locations in nine countries around the world, situated primarily in Australia, Brazil, Canada, Iceland, Norway, Spain, and the United States. Alcoa Corporation became an independent, publicly traded company on November 1, 2016, following its separation (the Separation Transaction) from its former parent company, Alcoa Inc. References herein to “ParentCo” refer to Alcoa Inc. and its consolidated subsidiaries through October 31, 2016, at which time it was renamed Arconic Inc. (Arconic) and since has been subsequently renamed Howmet Aerospace Inc. Basis of Presentation. The Consolidated Financial Statements of Alcoa Corporation are prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). In accordance with GAAP, certain situations require management to make estimates based on judgments and assumptions, which may affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements. They also may affect the reported amounts of revenues and expenses during the reporting periods. Management uses historical experience and all available information to make these estimates. Management regularly evaluates the judgments and assumptions used in its estimates, and results could differ from those estimates upon future events and their effects or new information. Principles of Consolidation. The Consolidated Financial Statements of the Company include the accounts of Alcoa Corporation and companies in which Alcoa Corporation has a controlling interest, including those that comprise the Alcoa World Alumina & Chemicals (AWAC) joint venture (see below). Intercompany transactions have been eliminated. The equity method of accounting is used for investments in affiliates and other joint ventures over which the Company has significant influence but does not have effective control. Investments in affiliates in which Alcoa Corporation cannot exercise significant influence are accounted at cost less any impairment, a measurement alternative in accordance with GAAP. AWAC is an unincorporated global joint venture between Alcoa Corporation and Alumina Limited and consists of several affiliated operating entities, which own, have an interest in, or operate the bauxite mines and alumina refineries within the Company’s Alumina segment (except for the Poços de Caldas mine and refinery, portions of the São Luís refinery, and investment in Mineração Rio do Norte S.A. (MRN) until its sale in April 2022, all in Brazil) and a portion (55%) of the Portland smelter (Australia) within the Company’s Aluminum segment. Alcoa Corporation owns 60% and Alumina Limited owns 40% of these individual entities, which are consolidated by the Company for financial reporting purposes and include Alcoa of Australia Limited (AofA), Alcoa World Alumina LLC (AWA), Alcoa World Alumina Brasil Ltda. (AWAB), and Alúmina Española, S.A. (Española). Alumina Limited’s interest in the equity of such entities is reflected as Noncontrolling interest on the accompanying Consolidated Balance Sheet. Management evaluates whether an Alcoa Corporation entity or interest is a variable interest entity and whether the Company is the primary beneficiary. Consolidation is required if both of these criteria are met. Alcoa Corporation does not have any variable interest entities requiring consolidation. Related Party Transactions. Alcoa Corporation buys products from and sells products to various related companies, consisting of entities in which the Company retains a 50% or less equity interest, at negotiated prices between the two parties. These transactions were not material to the financial position or results of operations of Alcoa Corporation for all periods presented. |
Summary of Significant Accounting Policies |
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Accounting Policies [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary of Significant Accounting Policies | B. Summary of Significant Accounting Policies Cash Equivalents. Cash equivalents are highly liquid investments purchased with an original maturity of three months or less. Restricted Cash. Restricted cash is included with Cash and cash equivalents when reconciling the Cash and cash equivalents and restricted cash at beginning of year and Cash and cash equivalents and restricted cash at end of year on the accompanying Statement of Consolidated Cash Flows. Current restricted cash amounts are reported in Prepaid expenses and other current assets on the accompanying Consolidated Balance Sheet. Noncurrent restricted cash amounts are reported in Other noncurrent assets on the accompanying Consolidated Balance Sheet (see Note U for a reconciliation of Cash and cash equivalents and restricted cash). Inventory Valuation. Inventories are carried at the lower of cost or net realizable value, with the cost of inventories principally determined under the average cost method. Properties, Plants, and Equipment. Properties, plants, and equipment are recorded at cost. Interest related to the construction of qualifying assets is capitalized as part of the construction costs. Depreciation is recorded principally on the straight-line method over the estimated useful lives of the assets. Depreciation is recorded on temporarily idled facilities until such time management approves a permanent closure. The following table details the weighted average useful lives of structures and machinery and equipment by type of operation (numbers in years):
Repairs and maintenance are charged to expense as incurred while costs for significant improvements that add productive capacity or that extend the useful life are capitalized. Gains or losses from the sale of assets are generally recorded in Other expenses (income), net. Properties, plants, and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets (asset group) may not be recoverable. Recoverability of assets is determined by comparing the estimated undiscounted net cash flows of the operations related to the assets (asset group) to their carrying amount. An impairment loss would be recognized when the carrying amount of the assets (asset group) exceeds the fair value. The amount of the impairment loss to be recorded is calculated as the excess of the carrying value of the assets (asset group) over their fair value, with fair value determined using the best information available, which generally is a discounted cash flow (DCF) model. The determination of what constitutes an asset group, the associated estimated undiscounted net cash flows, and the estimated useful lives of assets also require significant judgments. Leases. The Company determines whether an arrangement is a lease at the inception of the arrangement based on the terms and conditions in the contract. A contract contains a lease if there is an identified asset which the Company has the right to control. Lease right-of-use (ROU) assets are included in Properties, plants, and equipment, net with the corresponding operating lease liabilities included within Other current liabilities and Other noncurrent liabilities and deferred credits on the accompanying Consolidated Balance Sheet. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company uses its incremental borrowing rate at the commencement date in determining the present value of lease payments unless a rate is implicit in the lease. Lease terms include options to extend the lease when it is reasonably certain that those options will be exercised. Leases with an initial term of 12 months or less, including anticipated renewals, are not recorded on the Consolidated Balance Sheet. The Company made a policy election not to record any non-lease components of a lease agreement in the lease liability. Variable lease payments are not presented as part of the ROU asset or liability recorded at the inception of a contract. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. Equity Investments. Alcoa invests in a number of privately-held companies, primarily through joint ventures and consortia, which are accounted for using the equity method. The equity method is applied in situations where the Company has the ability to exercise significant influence, but not control, over the investee. Management reviews equity investments for impairment whenever certain indicators are present suggesting that the carrying value of an investment is not recoverable. Deferred Mining Costs. Alcoa incurs deferred mining costs during the development stage of a mine life cycle. Such costs include the construction of access and haul roads, detailed drilling and geological analysis to further define the grade and quality of the known bauxite, and overburden removal costs. These costs relate to sections of the related mines where the Company is currently extracting bauxite or preparing for production in the near term. These sections are outlined and planned incrementally and generally are mined over periods ranging from to five years, depending on specific mine plans. The amount of geological drilling and testing necessary to determine the economic viability of the bauxite deposit being mined is such that the reserves are considered to be proven. Deferred mining costs are amortized on a units-of-production basis and included in Other noncurrent assets on the accompanying Consolidated Balance Sheet. Goodwill and Other Intangible Assets. Goodwill is not amortized but is reviewed for impairment annually (in the fourth quarter) or more frequently if indicators of impairment exist or if a decision is made to sell or exit a business.
Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. Beginning in January 2023, the Company changed its operating segments, by combining the Bauxite and Alumina segments, and reported its financial results in the following two segments: (i) Alumina and (ii) Aluminum (see Note E). The Company has three reporting units, of which two are included in the Aluminum segment (smelting/casting and energy generation). The remaining reporting unit is the Alumina segment. Of these three reporting units, only contains goodwill (see Note L). Goodwill is tested for impairment by assessing qualitative factors to determine whether it is more likely than not (greater than 50%) that the fair value of the reporting unit is less than its carrying amount or performing a quantitative assessment using a discounted cash flow model. If the qualitative assessment indicates a possible impairment, then a quantitative impairment test is performed to determine the fair value of the reporting unit using a discounted cash flow method. Otherwise, no further analysis is required. Under the quantitative assessment, the evaluation of impairment involves comparing the current fair value of each reporting unit to its carrying value, including goodwill. In the event the estimated fair value of a reporting unit is less than the carrying value, an impairment loss equal to the excess of the reporting unit’s carrying value over its fair value not to exceed the total amount of goodwill applicable to that reporting unit would be recognized. Alcoa’s policy for its annual review of goodwill is to perform the quantitative impairment test for its reporting unit containing goodwill at least once during every three-year period. Intangible assets with finite useful lives are amortized generally on a straight-line basis over the periods benefited. The following table details the weighted average useful lives of software and other intangible assets by type of operation (numbers in years):
Asset Retirement Obligations. Alcoa recognizes asset retirement obligations (AROs) related to legal obligations associated with the standard operation of bauxite mines, alumina refineries, and aluminum smelters. These AROs consist primarily of costs associated with mine reclamation, closure of bauxite residue areas, spent pot lining and regulated waste materials disposal, and landfill closure. Additionally, costs are recorded as AROs upon management’s decision to permanently close and demolish certain structures and for any significant lease restoration obligations. The fair values of these AROs are recorded on a discounted basis at the time the obligation is incurred and accreted over time for the change in present value; related accretion is recorded as a component of Cost of goods sold. Additionally, the Company capitalizes asset retirement costs by increasing the carrying amount of the related long-lived assets and depreciating these assets over their remaining useful life. The fair values for AROs are determined using significant assumptions, including engineering designs for construction or closure, materials and services costs, regulatory requirements, volume of regulated material to be removed, disposition of demolition materials, and timing to complete construction or closure. Subsequent adjustments to estimates of previously established AROs for current operations are capitalized by increasing the carrying amount of the related long-lived assets and depreciating these assets over their remaining useful life. Adjustments to estimates of AROs for closed locations are charged to Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note R). Certain conditional asset retirement obligations related to alumina refineries, aluminum smelters, and energy generation facilities have not been recorded in the Consolidated Financial Statements due to uncertainties surrounding the ultimate settlement date. The fair value of these asset retirement obligations will be recorded when a reasonable estimate of the ultimate settlement date can be made. Environmental Matters. Environmental related expenditures for current operations are expensed as a component of Cost of goods sold or capitalized, as appropriate. Expenditures relating to existing conditions caused by past operations, generally for closed locations which will not contribute to future revenues, are charged to Restructuring and other charges, net. Liabilities are recorded when remediation costs are probable and can be reasonably estimated. In instances where the Company has ongoing monitoring and maintenance responsibilities, it is Alcoa’s policy to maintain a reserve equal to five years of expected costs. The liability is continuously reviewed and adjusted to reflect current remediation progress, rate and pricing changes, actual volumes of material requiring management, changes to the original assumptions regarding how the site was to be remediated, and other factors that may be relevant, including changes in technology or regulations. The estimates may also include costs related to other potentially responsible parties to the extent that Alcoa has reason to believe such parties will not fully pay their proportionate share. Litigation Matters. For asserted claims and assessments, liabilities are recorded when an unfavorable outcome of a matter is deemed to be probable and the loss is reasonably estimable. With respect to unasserted claims or assessments, liabilities are recorded when the probability that an assertion will be made is likely, an unfavorable outcome of the matter is deemed to be probable, and the loss is reasonably estimable. Legal matters are reviewed on a continuous basis to determine if there has been a change in management’s judgment regarding the likelihood of an unfavorable outcome or the estimate of a potential loss. Legal costs, which are primarily for general litigation, environmental compliance, tax disputes, and general corporate matters, are expensed as incurred. Revenue Recognition. The Company recognizes revenue when it satisfies a performance obligation(s) in accordance with the provisions of a customer order or contract. This is achieved when control of the product has been transferred to the customer, which is generally determined when title, ownership, and risk of loss pass to the customer, all of which occurs upon shipment or delivery of the product. The shipping terms vary across all businesses and depend on the product, the country of origin, and the type of transportation. Accordingly, the sale of Alcoa’s products to its customers represent single performance obligations for which revenue is recognized at a point in time, except for the Company’s Energy product division in which the customer simultaneously receives and consumes electricity (see Note E). Revenue is based on the consideration the Company expects to receive in exchange for its products. Returns and other adjustments have not been material. Based on the foregoing, no significant judgment is required to determine when control of a product has been transferred to a customer. The Company considers shipping and handling activities as costs to fulfill the promise to transfer the related products. As a result, customer payments of shipping and handling costs are recorded as a component of revenue. Taxes collected (e.g., sales, use, value added, excise) from its customers related to the sale of its products are remitted to governmental authorities and excluded from Sales. Cost of goods sold. The Company includes the following in Cost of goods sold: operating costs of our two segments, excluding depreciation, depletion, and amortization, but including all production related costs: raw materials consumed; purchases of metal for consumption; conversion costs, such as labor, materials, and utilities; equity earnings of certain investments integral to the Company’s supply chain; and plant administrative expenses. Also included in Cost of goods sold are: costs related to the Transformation function, which focuses on the management of expenses and obligations of previously closed operations; pension and other postretirement benefit service cost for employees maintaining closed locations; purchases of bauxite from offtake or other supply agreements, alumina to satisfy customer commitments, and metal for trade; and other costs not included in the operating costs of the segments. Selling, general administrative, and other expenses. The Company includes the costs of corporate-wide functional support in Selling, general administrative, and other expenses. Such costs include: executive; sales; marketing; strategy; operations administration; finance; information technology; legal; human resources; and government affairs and communications. Stock-Based Compensation. Compensation expense for employee equity grants is recognized using the non-substantive vesting period approach, in which the expense is recognized ratably over the requisite service period based on the grant date fair value. Forfeitures are accounted for as they occur. The fair value of performance stock units containing a market condition is valued using a Monte Carlo valuation model. Determining the fair value at the grant date requires judgment, including estimates for the average risk-free interest rate, and volatility. These assumptions may differ significantly between grant dates because of changes in the actual results of these inputs that occur over time. As of January 1, 2021, the Company no longer grants stock options. Refer to Note N for more information regarding stock-based compensation. Pension and Other Postretirement Benefits. Alcoa sponsors several defined benefit pension plans and health care postretirement benefit plans. The Company recognizes on a plan-by-plan basis the net funded status of these pension and postretirement benefit plans as either an asset or a liability on its Consolidated Balance Sheet. The net funded status represents the difference between the fair value of each plan’s assets and the benefit obligation of the respective plan. The benefit obligation represents the present value of the estimated future benefits the Company currently expects to pay to plan participants based on past service. Unrecognized gains and losses related to the plans are deferred in Accumulated other comprehensive loss on the Consolidated Balance Sheet until amortized into earnings. The plan assets and benefit obligations are measured at the end of each year or more frequently, upon the occurrence of certain events such as a significant plan amendment, settlement, or curtailment. For interim plan remeasurements, it is the Company’s policy to record the related accounting impacts within the same quarter as the triggering event. Liabilities and expenses for pension and other postretirement benefits are determined using actuarial methodologies and incorporate significant assumptions, including the interest rate used to discount the future estimated liability, the expected long-term rate of return on plan assets, and several assumptions relating to the employee workforce (salary increases, health care cost trend rates, retirement age, and mortality). The yield curve model used to develop the discount rate parallels the plans’ projected cash flows and has a weighted average duration of 10 years. The underlying cash flows of the high-quality corporate bonds included in the model exceed the cash flows needed to satisfy the Company’s plan obligations multiple times. If a deep market of high-quality corporate bonds does not exist in a country, then the yield on government bonds plus a corporate bond yield spread is used. The expected long-term rate of return on plan assets is generally applied to a five-year market-related value of plan assets (a four-year average or the fair value at the plan measurement date is used for certain non-U.S. plans). The process used by management to develop this assumption is one that relies on forward-looking investment returns by asset class. Management incorporates expected future investment returns on current and planned asset allocations using information from various external investment managers and consultants, as well as management’s own judgment. Mortality rate assumptions are based on mortality tables and future improvement scales published by third parties, such as the Society of Actuaries, and consider other available information including historical data as well as studies and publications from reputable sources. A change in one or a combination of these assumptions, or the effects of actual results differing from assumptions, could have a material impact on Alcoa’s projected benefit obligation. These changes or differences are recorded in Accumulated other comprehensive loss and are amortized into earnings as a component of the net periodic benefit cost (income) over the average future working lifetime or average remaining life expectancy, as appropriate, of the plan’s participants. One-time accounting impacts, such as curtailment and settlement losses (gains), are recognized immediately and are reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net on the accompanying Statement of Consolidated Operations. Refer to Note O for more information regarding pension and other postretirement benefits including accounting impacts of current year actions. Derivatives and Hedging. Derivatives are held for purposes other than trading and are part of a formally documented risk management program. Alcoa accounts for hedges of firm customer commitments for aluminum as fair value hedges. The fair values of the derivatives and changes in the fair values of the underlying hedged items are reported as assets and liabilities in the Consolidated Balance Sheet. Changes in the fair values of these derivatives and underlying hedged items generally offset and are recorded each period in Sales, consistent with the underlying hedged item. The Company accounts for certain hedges of foreign currency exposures and certain forecasted transactions as cash flow hedges. The fair values of the derivatives are recorded as assets and liabilities in the Consolidated Balance Sheet. The changes in the fair values of these derivatives are recorded in Other comprehensive (loss) income and are reclassified to Sales, Cost of goods sold, or Other expenses (income), net in the period in which earnings are impacted by the hedged items or in the period that the transaction no longer qualifies as a cash flow hedge. These contracts cover the same periods as known or expected exposures, generally not exceeding five years. If no hedging relationship is designated, the derivative is marked to market through Other expenses (income), net. Cash flows from derivatives are recognized in the Statement of Consolidated Cash Flows in a manner consistent with the underlying transactions. Income Taxes. The provision for income taxes is determined using the asset and liability approach of accounting for income taxes. Under this approach, the provision for income taxes represents income taxes paid or payable (or received or receivable) for the current year plus the change in deferred taxes during the year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid, resulting from differences between the financial and tax bases of Alcoa’s assets and liabilities and are adjusted for changes in tax rates and tax laws when enacted. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not (greater than 50%) that a tax benefit will not be realized. In evaluating the need for a valuation allowance, management applies judgment in assessing all available positive and negative evidence and considers all potential sources of taxable income. Deferred tax assets for which no valuation allowance is recorded may not be realized upon changes in facts and circumstances, resulting in a future charge to establish a valuation allowance. Existing valuation allowances are re-examined under the same standards of positive and negative evidence. If it is determined that it is more likely than not that a deferred tax asset will be realized, the appropriate amount of the valuation allowance, if any, is released. Deferred tax assets and liabilities are also re-measured to reflect changes in underlying tax rates due to law changes and the granting and lapse of tax holidays. Tax benefits related to uncertain tax positions taken or expected to be taken on a tax return are recorded when such benefits meet a more likely than not threshold. Otherwise, these tax benefits are recorded when a tax position has been effectively settled, which means that the statute of limitations has expired or the appropriate taxing authority has completed their examination even though the statute of limitations remains open. Interest and penalties related to uncertain tax positions are recognized as part of the provision for income taxes and are accrued in the period that such interest and penalties would be applicable under relevant tax law until such time that the related tax benefits are recognized. Foreign Currency. The local currency is the functional currency for Alcoa’s significant operations outside the United States, except for certain operations in Canada and Iceland, and a holding and trading company in the Netherlands, where the U.S. dollar is used as the functional currency. The determination of the functional currency for Alcoa’s operations is made based on the appropriate economic and management indicators. Where local currency is the functional currency, assets and liabilities are translated into U.S. dollars using period end exchange rates and income and expenses are translated using the average exchange rates for the reporting period. Unrealized foreign currency translation gains and losses are deferred in Accumulated other comprehensive loss on the Consolidated Balance Sheet. Recently Adopted Accounting Guidance. On January 1, 2023, the Company adopted Accounting Standard Update (ASU) No. 2022-04 which requires a buyer in a supplier finance program to disclose qualitative and quantitative information about its supplier finance programs, including the key terms of the program, the amount of obligations outstanding at the end of the reporting period, a description of where those obligations are presented in the balance sheet, and effective January 1, 2024, a roll-forward of such amounts during the annual period. The adoption of this guidance resulted in enhanced disclosures regarding these programs (see Note V) and did not have a material impact on the Company's Consolidated Financial Statements. Recently Issued Accounting Guidance. In December 2023, the Financial Accounting Standards Board (FASB) issued ASU No. 2023-09 which includes changes to income tax disclosures, including greater disaggregation of information in the rate reconciliation and disclosure of taxes paid by jurisdiction. The guidance is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. The adoption of this guidance will provide enhanced disclosures regarding income taxes and will not have a material impact on the Company’s financial statements. In November 2023, the FASB issued ASU No. 2023-07 which requires disclosure of significant segment expenses regularly provided to the chief operating decision maker (CODM), other segment items (not included in significant segment expenses for each reportable segment), the title and position of the CODM, and an explanation of how the CODM uses the reported measure of segment profit or loss to assess segment performance and allocate resources. The guidance is effective for fiscal years beginning after December 15, 2023 on an annual basis and beginning after December 15, 2024 on an interim basis. Early adoption is permitted. The adoption of this guidance will provide enhanced disclosures regarding reportable segments and will not have a material impact on the Company’s financial statements. |
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Divestitures |
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Dec. 31, 2023 | |
| Business Combinations [Abstract] | |
| Divestitures | C. Divestitures Rockdale Site During the fourth quarter of 2021, the Company completed the sale of land and industrial assets at the previously closed Rockdale smelter site in the state of Texas in a transaction valued at $240. Upon closing of the transaction, the Company received $230 in cash and recorded a net gain of $202 in Other expenses (income), net (pre- and after-tax; see Note U) on the Statement of Consolidated Operations. Eastalco Site During the second quarter of 2021, the Company completed the sale of land at the previously closed Eastalco smelter site in the state of Maryland in a transaction valued at $100. Upon closing of the transaction, the Company received $94 in cash and recorded a gain of $90 in Other expenses (income), net ($90 pre- and $89 after-tax; see Note U) on the Statement of Consolidated Operations.
Warrick Rolling Mill In March 2021, Alcoa completed the sale of its rolling mill located at Warrick Operations (Warrick Rolling Mill), an integrated aluminum manufacturing site near Evansville, Indiana (Warrick Operations), to Kaiser Aluminum Corporation (Kaiser) for total consideration of approximately $670, which included the assumption of $69 in other postretirement benefit liabilities. The Company recorded a net gain of $30 in Other expenses (income), net (pre- and after-tax, see Note U) on the Statement of Consolidated Operations. Upon the closing of the transaction, the Company recorded estimated liabilities for future site separation commitments and remaining transaction costs associated with the sales agreement. The Company recorded a charge of $17 and $8 in 2023 and 2022 in Other expenses (income), net, respectively, related to additional costs of existing site separation commitments. In 2023 and 2022, the Company spent $52 and $37 against the reserve, respectively. The remaining balance of $11 at December 31, 2023 is expected to be spent in 2024. The cash spent against the reserve is included in Cash provided from (used for) financing activities on the Statement of Consolidated Cash Flows. |
Restructuring and Other Charges, Net |
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| Restructuring and Related Activities [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Restructuring and Other Charges, Net | D. Restructuring and Other Charges, Net Restructuring and other charges, net were comprised of the following:
Severance and employee termination costs were recorded based on approved detailed action plans submitted by the operating locations that specified positions to be eliminated, benefits to be paid under existing severance plans, union contracts or statutory requirements, and the expected timetable for completion of the plans. 2023 Actions. In 2023, Alcoa Corporation recorded Restructuring and other charges, net, of $184 which were primarily comprised of the following components: • Non-cash settlement charges related to pension benefits (see Note O): o $21 related to the purchase of group annuity contracts to transfer approximately $235 of pension obligations and assets associated with defined benefit pension plans for approximately 530 Canadian retirees and beneficiaries; • Charges related to portfolio actions: o $101 for the permanent closure of the previously curtailed Intalco (Washington) smelter (see below); o $53 for the updated viability agreement for the San Ciprián (Spain) smelter; and, o $11 for employee termination and severance costs, primarily related to the Kwinana refinery productivity program (see below); • Other net charges: o $17 to record additional environmental and asset retirement related reserves at previously closed sites (see Note R and Note S); o $19 benefit for the sale of unused carbon credits at a previously closed site; o $1 to record additional asset retirement related reserves at Warrick Operations (Indiana) (see Note R); and, o $1 for additional take-or-pay contract costs related to the closed Wenatchee (Washington) and Intalco smelters; • Reversals: o $2 due to lower costs for demolition and remediation at previously closed sites (see Note R). In December 2023, Alcoa began the closure of a line at its Warrick Operations site in Indiana that had not operated since 2016 to allow for future capital investments to improve casting capabilities. The Company recorded a charge of $1 in Restructuring and other charges, net on the Statement of Consolidated Operations to establish reserves related to demolition obligations. Additionally, Alcoa recorded $1 in Cost of goods sold on the Statement of Consolidated Operations to write-off the remaining net book value of related inventory. In September 2023, the Company initiated productivity programs across its operations in Australia to mitigate the financial impacts of lower grade bauxite and to optimize operating levels. In connection with this program, the Company recorded Restructuring and other charges, net of $6 for employee termination and severance costs for approximately 90 employees at the Kwinana refinery. The restructuring action and associated cash outlays are anticipated to be complete by the end of the second quarter of 2024. In 2023, the Company spent $1 against the reserve. In March 2023, Alcoa Corporation announced the closure of the Intalco aluminum smelter, which had been fully curtailed since 2020. The Company recorded charges of $117 related to the closure, including a charge of $16 in Cost of goods sold on the Statement of Consolidated Operations to write-down remaining inventories to net realizable value and a charge of $101 in Restructuring and other charges, net on the Statement of Consolidated Operations. The restructuring charges were comprised of asset impairments of $50, environmental and demolition obligation reserves of $50, and severance and employee termination costs of $1 for the separation of approximately 12 employees. Cash outlays related to the permanent closure of the site in 2024 and 2025 are expected to be approximately $54 related to environmental and demolition obligation reserves, $4 of which was reserved for in prior periods, and $31 related to holding costs during the closure. At December 31, 2023, the separation of employees associated with this program was complete with $1 of payments made against the severance and employee termination cost reserve. In February 2023, the Company reached an updated viability agreement with the workers’ representatives of the San Ciprián smelter to commence the restart process in phases beginning in January 2024. The smelter was curtailed in January 2022 as a result of an agreement reached with the workers’ representatives in December 2021 (see below). Under the terms of the updated viability agreement, the Company is responsible for certain employee obligations during 2023 through 2025 and made commitments for capital improvements of $78. The Company recorded charges of $53 in Restructuring and other charges, net on the Statement of Consolidated Operations to establish the related reserve for employee obligations in 2023. Cash outlays related to these obligations were $7 in 2023 and the remainder is expected in 2024 and 2025. At December 31 2023, the Company has restricted cash of $91 to be made available for remaining capital improvement commitments at the site of $118 and smelter restart costs of $35 (see below). Restricted cash is included in Prepaid expenses and other current assets and Other noncurrent assets on the Consolidated Balance Sheet (see Note U). 2022 Actions. In 2022 Alcoa Corporation recorded Restructuring and other charges, net, of $696 which were primarily comprised of the following components: • Non-cash settlement charges related to pension benefits (see Note O): o $635 related to the purchase of group annuity contracts to transfer approximately $1,000 of pension obligations and assets associated with defined benefit pension plans for approximately 4,400 United States retirees and beneficiaries, as well as lump sum settlements; • Charges related to portfolio actions: o $79 for the agreement reached with the workers of the divested Avilés and La Coruña facilities to settle various legal disputes related to the 2019 divestiture (see Note S); o $58 for an asset impairment related to the sale of the Company’s interest in MRN (see Note H); and, o $29 related to the closure of the previously curtailed magnesium smelter facility in Addy (Washington) (see below); • Other charges and credits: o $26 to record additional environmental and asset retirement related reserves at previously closed sites (see Note R and Note S); and, o $7 net credit for revaluation of adjustments to take-or-pay contract reserves related to the closed Wenatchee and curtailed Intalco smelters; • Reversals: o $83 for the release of a valuation allowance on Brazil value added taxes (VAT) (see Note Q); and, o $34 due to lower costs for demolition and remediation at previously closed sites (see Note S). In July 2022, Alcoa made the decision to permanently close the previously curtailed magnesium smelter in Addy. The facility has been fully curtailed since 2001. The Company recorded a charge of $29 to establish reserves for environmental and demolition obligations in Restructuring and other charges, net on the Statement of Consolidated Operations in the third quarter of 2022. 2021 Actions. In 2021 Alcoa Corporation recorded Restructuring and other charges, net, of $1,128 which were comprised of the following components: • Non-cash settlement charges related to pension and certain other postretirement benefits (see Note O): o $858 related to the purchase of group annuity contracts to transfer approximately $1,500 of pension obligations and assets associated with defined benefit pension plans for approximately 14,000 United States retirees and beneficiaries, as well as lump sum settlements; o $63 related to the purchase of a group annuity contract to transfer approximately $55 of pension obligations and assets associated with a Suriname pension plan for approximately 800 retirees and beneficiaries; o $47 related to lump sum settlements; and, o Net $9 related to the settlement and curtailment of certain other postretirement benefits resulting from the sale of the Warrick Rolling Mill; • Charges related to portfolio actions taken as part of the Company’s ongoing strategic review (see details below): o $80 related to the closure of the previously curtailed aluminum smelter facility in Wenatchee (Washington); o $62 related to the agreement reached with the workers at the San Ciprián aluminum smelter to curtail smelting capacity; and, o $27 related to the closure of the previously curtailed anode facility in Lake Charles (Louisiana); • Other charges: o $13 for additional take-or-pay contract costs related to the curtailed Wenatchee and Intalco smelters; o $11 to record additional environmental and asset retirement related reserves (see Note R and Note S); and, o $3 for several other immaterial items; • Reversals: o $6 for a take-or-pay energy-related obligation at the Alumar (Brazil) smelter no longer required due to the restart; o $17 related to the divestiture of the Avilés and La Coruña entities (see below); and, o $22 due to lower costs for demolition and remediation related to previously established reserves (see Note R and Note S). In December 2021, the Company announced the two-year curtailment of 228 kmt of smelting capacity at the San Ciprián smelter. The temporary curtailment, which began at the end of January 2022, was the result of an agreement reached with the workers' representatives at the site to suspend production due to exorbitant energy prices in Spain. Under the terms of the agreement, the Company is responsible for certain employee obligations during 2022 and 2023, and committed to restart the smelter beginning in January 2024. The Company recorded charges of $62 in Restructuring and other charges, net on the Statement of Consolidated Operations to establish the related reserve for employee obligations in 2021. Cash payments were $31 and $26 in 2023 and 2022, respectively and this program is complete as of December 31, 2023. Additionally, the Company made restricted cash available for capital improvements at the site of $68 and smelter restart costs of $35 (see above). During the fourth quarter of 2021, as part of the Company’s ongoing strategic portfolio review, the Company announced the permanent closure of the Wenatchee aluminum smelter. The smelter has been fully curtailed since 2015. Charges related to the closure totaled $90 in the fourth quarter of 2021 and included a charge of $10 for the write-down of remaining inventories to net realizable value recorded in Cost of goods sold on the Statement of Consolidated Operations and a charge of $80 recorded in Restructuring and other charges, net on the Statement of Consolidated Operations. The restructuring charges were comprised of: $30 to write-off the remaining net book value of various assets; $23 of asset impairments; $21 to establish reserves related to environmental and demolition obligations; $5 related to take-or-pay contractual obligations; and $1 of severance and employee termination costs from the separation of approximately 10 employees. Cash payments were $3 and $1 in 2023 and 2022, respectively. During the third quarter of 2021, as part of the Company’s ongoing strategic portfolio review, the Company announced the decision to permanently close the previously curtailed anode facility in Lake Charles. The anode facility within the Lake Charles site has been fully curtailed since 2015. The Company recorded charges of $27 in the third quarter of 2021, which were recorded in Restructuring and other charges, net on the Statement of Consolidated Operations, comprised of asset impairments of $22 and cash-based charges for closure and asset retirement obligations of $5. The closure was completed in September 2022. The decision to permanently close the facility was made as part of the Company’s ongoing portfolio review. The Company’s petroleum coke calciner located at the same site in Lake Charles remains in operation, unaffected by the closure of the anode facility. Alcoa Corporation does not include Restructuring and other charges, net in the results of its reportable segments. The impact of allocating such charges to segment results would have been as follows:
(1) Beginning in January 2023, the Company changed its operating segments, by combining the Bauxite and Alumina segments, and reported its financial results in the following two segments: (i) Alumina and (ii) Aluminum (see Note E). Activity and reserve balances for restructuring charges were as follows:
The activity and reserve balances include only Restructuring and other charges, net that impact the reserves for Severance and employee termination costs and Other costs. Restructuring and other charges, net that affected other accounts such as Investments (see Note H), Accrued pension benefits and Accrued other postretirement benefits (see Note O), Asset retirement obligations (see Note R), and Environmental remediation (see Note S) are excluded from the above activity and balances. Reversals and other include reversals of previously recorded liabilities and foreign currency translation impacts. The current portion of the reserve balance is reflected in Other current liabilities on the Consolidated Balance Sheet and the noncurrent portion of the reserve balance is reflected in Other noncurrent liabilities and deferred credits on the Consolidated Balance Sheet. The noncurrent portion of the reserve was $15 and $3 at December 31, 2023 and 2022, respectively. |
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Segment and Related Information |
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| Segment Reporting [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Segment and Related Information | E. Segment and Related Information Segment Information Alcoa Corporation is a producer of bauxite, alumina, and aluminum products. Beginning in January 2023, the financial information provided to the chief operating decision maker (CODM) for the activities of the bauxite mines and the alumina refineries was combined into the Alumina segment, and accordingly the Company changed its operating segments. Beginning with the first quarter of 2023, the Company reported its financial results in the following two segments: (i) Alumina and (ii) Aluminum. Segment information for all prior periods presented has been updated to reflect the new segment structure. Segment performance under Alcoa Corporation’s management reporting system is evaluated based on a number of factors; however, the primary measure of performance is the Adjusted EBITDA (Earnings before interest, taxes, depreciation, and amortization) for each segment. The Company calculates Segment Adjusted EBITDA as Total sales (third-party and intersegment) minus the following items: Cost of goods sold; Selling, general administrative, and other expenses; and Research and development expenses. Alcoa Corporation’s Segment Adjusted EBITDA may not be comparable to similarly titled measures of other companies. The CODM function regularly reviews the financial information, including Adjusted EBITDA, of these two operating segments to assess performance and allocate resources. Segment assets include, among others, customer receivables (third-party and intersegment), inventories, properties, plants, and equipment, and equity investments. The accounting policies of the segments are the same as those described in the Summary of Significant Accounting Policies (see Note B). Transactions between segments are established based on negotiation between the parties. Differences between segment totals and Alcoa Corporation’s consolidated totals for line items not reconciled are in Corporate.
The following are detailed descriptions of Alcoa Corporation’s reportable segments: Alumina. This segment represents the Company’s worldwide refining system, including the mining of bauxite, which is then refined into alumina. The alumina produced by this segment is sold primarily to internal and external aluminum smelter customers; a portion of the alumina is sold to external customers who process it into industrial chemical products. Approximately two-thirds of Alumina’s production is sold under supply contracts to third parties worldwide, while the remainder is used internally by the Aluminum segment. Alumina produced by this segment and used internally is transferred to the Aluminum segment at prevailing market prices. A portion of this segment’s third-party sales are completed through the use of alumina traders. Generally, this segment’s sales are transacted in U.S. dollars while costs and expenses are transacted in the local currency of the respective operations, which are the Australian dollar, the Brazilian real, and the euro. Most of the operations that comprise the Alumina segment are part of AWAC (see Principles of Consolidation in Note A). A portion of this segment’s bauxite production represents the offtake from equity method investments in Brazil (prior to the MRN sale in April 2022) and Guinea, as well as AWAC’s share of bauxite production related to an equity investment in Saudi Arabia. Bauxite mined is primarily used internally within the Alumina segment; a portion of the bauxite is sold to external customers. Bauxite sales to third-parties are conducted on a contract basis. This segment also includes AWAC’s 25.1% ownership interest in a mining and refining joint venture company in Saudi Arabia (see Note H). Aluminum. This segment consists of the Company’s (i) worldwide smelting and casthouse system, which processes alumina into primary aluminum, and (ii) portfolio of energy assets in Brazil, Canada, and the United States. Aluminum’s combined smelting and casting operations produce primary aluminum products, nearly all of which are sold to external customers and traders. The smelting operations produce molten primary aluminum, which is then formed by the casting operations into either common alloy ingot (e.g., t-bar, sow, standard ingot) or into value-add ingot products (e.g., foundry, billet, rod, and slab). A variety of external customers purchase the primary aluminum products for use in fabrication operations, which produce products primarily for the transportation, building and construction, packaging, wire, and other industrial markets. Results from the sale of aluminum powder and scrap are also included in this segment, as well as the impacts of embedded aluminum derivatives (see Note P) related to energy supply contracts. The energy assets supply power to external customers in Brazil and the United States, as well as internal customers in the Aluminum segment (Canadian smelters and Warrick (Indiana) smelter) and, to a lesser extent, the Alumina segment (Brazilian refineries). Results from the Warrick Rolling Mill are included in this segment through the first quarter of 2021 (see Note C). Alcoa continues to own and operate the Warrick Operations aluminum smelter and the power plant. Generally, this segment’s aluminum sales are transacted in U.S. dollars while costs and expenses of this segment are transacted in the local currency of the respective operations, which are the U.S. dollar, the euro, the Norwegian krone, the Icelandic króna, the Canadian dollar, the Brazilian real, and the Australian dollar. This segment also includes Alcoa Corporation’s 25.1% ownership interest in a smelting joint venture company in Saudi Arabia (see Note H). The operating results, capital expenditures, and assets of Alcoa Corporation’s reportable segments were as follows:
The following tables reconcile certain segment information to consolidated totals:
(1) Transformation includes, among other items, the Adjusted EBITDA of previously closed operations. (2) Corporate expenses are composed of general administrative and other expenses of operating the corporate headquarters and other global administrative facilities, as well as research and development expenses of the corporate technical center. (3) Other includes certain items that are not included in the Adjusted EBITDA of the reportable segments.
Product Information Alcoa Corporation has four product divisions and one divested product division as follows: Bauxite—Bauxite is a reddish clay rock that is mined from the surface of the earth’s terrain. This ore is the basic raw material used to produce alumina and is the primary source of aluminum. Alumina—Alumina is an oxide that is extracted from bauxite and is the basic raw material used to produce primary aluminum. This product can also be consumed for non-metallurgical purposes, such as industrial chemical products. Primary aluminum—Primary aluminum is metal in the form of a common alloy ingot or a value-add ingot (e.g., foundry, billet, rod, and slab). These products are sold primarily to customers that produce products for the transportation, building and construction, packaging, wire, and other industrial markets, and traders. Energy—Energy is the generation of electricity, which is sold in the wholesale market to traders, large industrial consumers, distribution companies, and other generation companies. Flat-rolled aluminum—Flat-rolled aluminum is metal in the form of sheet, which is sold primarily to customers that produce beverage and food cans, including body, tab, and end stock. As noted above, the Company sold the Warrick Rolling Mill in March 2021 which represented the Company’s only Flat-rolled aluminum asset. The results of the Warrick Rolling Mill are included in this product division through the first quarter of 2021. The following table represents the general commercial profile of the Company’s Bauxite, Alumina, and Primary aluminum product divisions (see text below table for Energy):
(1) API (Alumina Price Index) is a pricing mechanism that is calculated by the Company based on the weighted average of a prior month’s daily spot prices published by the following three indices: CRU Metallurgical Grade Alumina Price, Platts Metals Daily Alumina PAX Price, and FastMarkets Metal Bulletin Non-Ferrous Metals Alumina Index. (2) LME (London Metal Exchange) is a globally recognized exchange for commodity trading, including aluminum. The LME pricing component represents the underlying base metal component, based on quoted prices for aluminum on the exchange. The regional premium represents the incremental price over the base LME component that is associated with the physical delivery of metal to a particular region (e.g., the Midwest premium for metal sold in the United States). The product premium represents the incremental price for receiving physical metal in a particular shape or alloy. (3) CIF (cost, insurance, and freight) means that the Company pays for these items until the product reaches the buyer’s designated destination point related to transportation by vessel. DAP (delivered at place) means the same as CIF related to all methods of transportation. FOB (free on board) means that the Company pays for costs, insurance, and freight until the product reaches the seller’s designated shipping point. (4) The net number of days means that the customer is required to remit payment to the Company for the invoice amount within the designated number of days. LC Sight is a letter of credit that is payable immediately (usually within five to ten business days) after a seller meets the requirements of the letter of credit (i.e. shipping documents that evidence the seller performed its obligations as agreed to with a buyer). CAD (cash against documents) is a payment arrangement in which a seller instructs a bank to provide shipping and title documents to the buyer at the time the buyer pays in full the accompanying bill of exchange. For the Company’s Energy product division, sales of electricity are based on current market prices. Electricity is provided to customers on demand through a national or regional power grid; the customer simultaneously receives and consumes the electricity. Payment terms are generally within 10 days related to the previous 30 days of electricity consumption. The following table details Alcoa Corporation’s Sales by product division:
(1) Flat-rolled aluminum represented sales of the Warrick Rolling Mill through the sale of the facility in March 2021 (see Note C). (2) Other includes realized gains and losses related to embedded derivative instruments designated as cash flow hedges of forward sales of aluminum (see Note P). Geographic Area Information Geographic information for Third-party sales was as follows (based upon the country where the point of sale originated):
(1) Sales of a portion of the alumina from refineries in Australia and Brazil and most of the aluminum from smelters in Canada occurred in the United States. (2) Sales of aluminum off-take related to an interest in the Saudi Arabia joint venture (see Note H), occurred in Spain through most of the third quarter of 2021, and in the United States thereafter. (3) Sales of aluminum from smelters in Iceland and Norway occurred in Spain through most of the first quarter of 2021, and in the Netherlands thereafter. Geographic information for long-lived assets was as follows (based upon the physical location of the assets):
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Earnings Per Share |
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Earnings Per Share [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Earnings Per Share | F. Earnings Per Share Basic earnings per share (EPS) amounts are computed by dividing Net (loss) income attributable to Alcoa Corporation by the average number of common shares outstanding. Diluted EPS amounts assume the issuance of common stock for all potentially dilutive share equivalents outstanding. The share information used to compute basic and diluted EPS attributable to Alcoa Corporation common shareholders was as follows (shares in millions):
In 2023, basic average shares outstanding and diluted average shares outstanding were the same because the effect of potential shares of common stock was anti-dilutive. Had Alcoa generated net income in 2023, three million common share equivalents related to three million outstanding stock units and stock options combined would have been included in diluted average shares outstanding for the period. In 2022, basic average shares outstanding and diluted average shares outstanding were the same because the effect of potential shares of common stock was anti-dilutive. Had Alcoa generated net income in 2022, three million common share equivalents related to five million outstanding stock units and stock options combined would have been included in diluted average shares outstanding for the period. In 2021, options to purchase less than two hundred thousand shares of common stock outstanding as of December 31, 2021 at a weighted average exercise price of $38.67 per share were not included in the computation of diluted EPS because the exercise prices of these options were greater than the annual average market price of Alcoa Corporation’s common stock. |
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Accumulated Other Comprehensive Loss |
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| Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Accumulated Other Comprehensive Loss | G. Accumulated Other Comprehensive Loss The following table details the activity of the three components that comprise Accumulated other comprehensive loss for both Alcoa Corporation’s shareholders and Noncontrolling interest:
(1) These amounts were included in the computation of net periodic benefit cost for pension and other postretirement benefits. The amounts related to settlements and/or curtailments of certain pension and other postretirement benefits for Alcoa Corporation include $21, $633, and $952 for the years ended December 31, 2023, 2022, and 2021, respectively. The amounts related to settlements and/or curtailments of certain pension and other postretirement benefits for Noncontrolling interest include $0, ($1), and $25 for the years ended December 31, 2023, 2022, and 2021, respectively (see Note O). (2) These amounts were reported in Provision for income taxes on the accompanying Statement of Consolidated Operations. (3) These amounts were reported in Sales on the accompanying Statement of Consolidated Operations. (4) These amounts were reported in Cost of goods sold on the accompanying Statement of Consolidated Operations. (5) These amounts were included in Other (income) expenses, net on the accompanying Statement of Consolidated Operations. (6) In 2023, $5 was reported in Cost of goods sold and ($31) was reported in Sales on the accompanying Statement of Consolidated Operations. In 2022, $5 was reported in Cost of goods sold and ($10) was reported in Sales on the accompanying Statement of Consolidated Operations. (7) A positive amount indicates a corresponding charge to earnings and a negative amount indicates a corresponding benefit to earnings. |
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Investments |
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| Equity Method Investments and Joint Ventures [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Investments | H. Investments
Equity Investments. The following table summarizes information of Alcoa Corporation’s equity investments as of December 31, 2023 and 2022. In 2023, 2022, and 2021, Alcoa Corporation received $51, $127, and $50, respectively, in dividends from these equity investments. Each of the investees either owns the facility listed or has an ownership interest in an entity that owns the facility listed:
Saudi Arabia Joint Venture—Alcoa Corporation and Ma’aden have a 30-year (from December 2009) joint venture shareholders agreement (automatic extension for an additional 20 years, unless the parties agree otherwise or unless earlier terminated) setting forth the terms for the development, construction, ownership, and operation of an integrated aluminum complex in Saudi Arabia. The project developed by the joint venture consists of a bauxite mine from the Al Ba’itha bauxite deposit in the northern part of Saudi Arabia, an alumina refinery, a primary aluminum smelter, and an aluminum rolling mill. The joint venture is owned 74.9% by Ma’aden and 25.1% by Alcoa Corporation and originally consisted of three separate companies as follows: the bauxite mine and alumina refinery (Ma’aden Bauxite and Alumina Company; MBAC), the smelter (Ma’aden Aluminum Company; MAC), and the rolling mill (Ma’aden Rolling Company; MRC). In June 2019, Alcoa Corporation and Ma’aden amended the joint venture agreement that governs the operations of each of the three companies that comprise the joint venture. Under the terms of the agreement, Alcoa Corporation transferred its 25.1% interest in MRC to Ma’aden and, as a result, has no further direct or indirect equity interest in MRC. In accordance with the June 2019 amended joint venture agreement, Ma’aden’s put option and Alcoa Corporation’s call option, relating to additional interests in the joint venture, were exercisable for a period of six months after October 1, 2021. On March 31, 2022, Ma’aden’s and Alcoa’s put and call options, respectively, expired with neither party exercising their options. The results for the Saudi Arabia joint venture for the year ended December 31, 2022 include a charge related to a dispute with an industrial utility for periods in 2021 and 2022. Alcoa’s share of this charge was $21 which is included in Other expenses (income), net on the Statement of Consolidated Operations for the year ended December 31, 2022. The results for the Saudi Arabia joint venture for the year ended December 31, 2023 include an adjustment to the estimate for the settlement of this dispute. Alcoa’s share of this adjustment is $41 which is included in Other expenses (income), net on the Statement of Consolidated Operations for 2023. As of December 31, 2023 and 2022, the carrying value of Alcoa’s investment in this joint venture was $533 and $710, respectively. ELYSIS Limited Partnership—In June 2018, Alcoa Corporation, Rio Tinto Alcan Inc. (Rio Tinto), and Investissement Québec, a company wholly-owned by the Government of Québec, Canada, launched the ELYSIS Limited Partnership (ELYSIS). The purpose of this partnership is to advance larger scale development and commercialization of its patent-protected technology that produces oxygen and eliminates direct greenhouse gas emissions from the traditional aluminum smelting process. Alcoa and Rio Tinto plc, as general partners, each own a 48.235% stake in ELYSIS, and the Québec provincial government, as a limited partner, owns a 3.53% stake. The federal government of Canada and Apple Inc., as well as the Québec provincial government, are providing initial financing to the partnership. Through December 31, 2023, the Company has contributed $118 (C$155) toward its investment commitment in ELYSIS. The Company’s basis in the investment has been reduced to zero for its share of losses incurred to date. In addition to cash contributions, Alcoa is contributing approximately $3 annually to cover overhead expenses incurred by Alcoa and charged to the joint venture. As a result, the Company has $60 in unrecognized losses as of December 31, 2023 that will be recognized upon additional contributions into the partnership. The following table summarizes the profit and loss data for the respective periods ended December 31, as it relates to Alcoa Corporation’s equity investments. Information shown for the Saudi Arabia Joint Venture for all periods presented includes the combined balances for MAC and MBAC. The investments are grouped based on the nature of the investment. The Mining investments are part of the Alumina segment, while the Energy and Other investments are primarily part of the Aluminum segment.
The following table summarizes the balance sheet data for the respective periods ended December 31, as it relates to Alcoa Corporation’s equity investments.
On February 15, 2022, the Company signed an agreement to sell its share of its investment in MRN in Brazil for $10 to South32 Minerals S.A. Related to this transaction, the Company recorded an asset impairment of $58 in the first quarter of 2022 in Restructuring and other charges, net on the Statement of Consolidated Operations. On April 30, 2022, Alcoa completed the sale of its investment in MRN. An additional $30 in cash could be paid to the Company in the future if certain post-closing conditions related to future MRN mine development are satisfied. |
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Receivables |
12 Months Ended |
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Dec. 31, 2023 | |
| Receivables [Abstract] | |
| Receivables | I. Receivables On January 31, 2023, a wholly-owned special purpose entity (SPE) of the Company entered into a one-year agreement with a financial institution to sell up to $150 of certain customer receivables without recourse on a revolving basis. On August 27, 2023, the Company amended the agreement to decrease the amount of certain receivables that can be transferred from $150 to $130. On November 15, 2023, the Company amended the agreement to extend the termination date from January 30, 2024 to November 14, 2024. Company subsidiaries sell customer receivables to the SPE, which then transfers the receivables to the financial institution. The Company does not maintain effective control over the transferred receivables, and therefore accounts for the transfers as sales of receivables. Alcoa Corporation guarantees the performance obligations of the Company subsidiaries and unsold customer receivables are pledged as collateral to the financial institution to secure the sold receivables. At December 31, 2023, the SPE held unsold customer receivables of $104 pledged as collateral against the sold receivables. The Company continues to service the customer receivables that were transferred to the financial institution. As Alcoa collects customer payments, the SPE transfers additional receivables to the financial institution rather than remitting cash. In 2023, the Company sold gross customer receivables of $591, and reinvested collections of $477 from previously sold receivables, resulting in net cash proceeds from the financial institution of $114. Cash collections from previously sold receivables yet to be reinvested of $99 were included in Accounts payable, trade on the accompanying Consolidated Balance Sheet as of December 31, 2023. Cash received from sold receivables under the agreement are presented within operating activities in the Statement of Consolidated Cash Flows. |
Inventories |
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| Inventory Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Inventories | J. Inventories
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Properties, Plants, and Equipment, Net |
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| Properties, Plants, and Equipment, Net | K. Properties, Plants, and Equipment, Net
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Goodwill and Other Intangible Assets |
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| Goodwill and Intangible Assets Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Goodwill and Other Intangible Assets | L. Goodwill and Other Intangible Assets Goodwill, which is included in Other noncurrent assets on the accompanying Consolidated Balance Sheet, was as follows:
(1) The carrying value of Corporate’s goodwill is net of accumulated impairment losses of $742 as of both December 31, 2023 and 2022. As of December 31, 2023, the $142 of goodwill reflected in Corporate is allocated to Alcoa Corporation's Alumina reportable segment for purposes of impairment testing (see Note B). This goodwill is reflected in Corporate for segment reporting purposes because it is not included in management’s assessment of performance by the reportable segment. Changes in the carrying amount of goodwill were attributable to foreign currency translation as of December 31, 2023 and 2022. Management performed a quantitative assessment for the Alumina reporting unit in the fourth quarter 2023. The estimated fair value of the Alumina reporting unit was substantially in excess of its carrying value, resulting in no impairment. As a result of the January 2023 segment change, the Company reviewed the recoverability of the carrying value of goodwill of its Alumina reporting unit in the first quarter of 2023. The estimated fair value of the Alumina reporting unit substantially exceeded the reporting unit’s carrying value, resulting in no impairment. Other intangible assets, which are included in Other noncurrent assets on the accompanying Consolidated Balance Sheet, were as follows:
Computer software consists primarily of software costs associated with the enterprise business solution within Alcoa to drive common systems among all businesses. Amortization expense related to the intangible assets in the table above for the years ended December 31, 2023, 2022, and 2021 was $5, $7, and $11, respectively, and is expected to be approximately $10 annually from 2024 to 2028. |
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Debt |
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| Debt | M. Debt Short-term Borrowings.
Short-term borrowings are reported in Other current liabilities on the accompanying Consolidated Balance Sheet. Inventory Repurchase Agreements During 2023, the Company entered into inventory repurchase agreements whereby the Company sold aluminum to a third party and agreed to subsequently repurchase substantially similar inventory. The Company did not record sales upon each shipment of inventory and the net cash received of $56 related to these agreements was recorded in Short-term borrowings as of December 31, 2023. For the year ended December 31, 2023, the Company recorded borrowings of $117 and repurchased $61 of inventory related to these agreements. As of December 31, 2023, inventory sold of $56 was reflected in Prepaid expenses and other current assets on the Consolidated Balance Sheet. The cash received and subsequently paid under the inventory repurchase agreements is included in Cash provided from financing activities on the Statement of Consolidated Cash Flows for the year-ended December 31, 2023. Long-term Debt.
The principal amount of long-term debt maturing in each of the next five years is: $79 in 2024, $1 in each of 2025 and 2026, $750 in 2027, and $500 in 2028. At December 31, 2023, Other includes $78 related to a term loan that matures in November 2024. 144A Debt. 2029 Notes. In March 2021, Alcoa Nederland Holding B.V. (ANHBV), a wholly-owned subsidiary of Alcoa Corporation, completed a Rule 144A (U.S. Securities Act of 1933, as amended) debt issuance for $500 aggregate principal amount of 4.125% Senior Notes due 2029 (the 2029 Notes) with the following terms: • Net proceeds were approximately $493, reflecting a discount to the initial purchasers as well as issuance costs. The discount, as well as costs to complete the financing, were deferred and are being amortized to interest expense over the term; • Interest is paid semi-annually in March and September, which commenced September 30, 2021; • Indenture contains customary affirmative and negative covenants, see below; • Option to redeem on at least 10 days, but not more than 60 days, prior notice to the holders under multiple scenarios, including, in whole or in part, at any time, or from time to time after March 31, 2024, at a redemption price up to 102.063% of the principal amount, plus any accrued and unpaid interest; and, • Subject to repurchase upon the occurrence of a change in control repurchase event (as defined in the indenture) at a repurchase price in cash equal to 101% of the aggregate principal amount of the notes repurchased, plus any accrued and unpaid interest. The Company used the net proceeds of the 2029 Notes, together with cash on hand, to contribute $500 to its U.S. defined benefit pension plans applicable to salaried and hourly employees on April 1, 2021 (see Note O), to redeem in full $750 aggregate principal amount of the Company’s outstanding 6.75% Senior Notes due 2024 on April 7, 2021, and to pay transaction-related fees and expenses. 2027 Notes. In July 2020, ANHBV completed a Rule 144A debt issuance for $750 aggregate principal amount of 5.500% Senior Notes due 2027 (the 2027 Notes) with the following terms: • Net proceeds were approximately $736, reflecting a discount to the initial purchasers as well as issuance costs. The discount, as well as costs to complete the financing, were deferred and are being amortized to interest expense over the term; • Interest is paid semi-annually in June and December, which commenced on December 15, 2020; • Indenture contains customary affirmative and negative covenants, see below; • Option to redeem on at least 15 days, but not more than 60 days, prior notice to the holders under multiple scenarios, including, in whole or in part, at any time, or from time to time after June 15, 2023, at a redemption price up to 102.750% of the principal amount, plus any accrued and unpaid interest; and, • Subject to repurchase upon the occurrence of a change in control repurchase event (as defined in the indenture) at a repurchase price in cash equal to 101% of the aggregate principal amount of the notes repurchased, plus any accrued and unpaid interest. The Company used the net proceeds of the 2027 Notes for general corporate purposes, including adding cash to its balance sheet. 2028 Notes. In May 2018, ANHBV completed a Rule 144A debt issuance for $500 aggregate principal amount of 6.125% Senior Notes due 2028 (the 2028 Notes) with the following terms: • Net proceeds were approximately $492, reflecting a discount to the initial purchasers as well as issuance costs. The discount, as well as costs to complete the financing, were deferred and are being amortized to interest expense over the term; • Interest is paid semi-annually in November and May, which commenced November 15, 2018; • Indenture contains customary affirmative and negative covenants, see below; • Option to redeem on at least 30 days, but not more than 60 days, prior notice to the holders under multiple scenarios, including, in whole or in part, at any time, or from time to time after May 2023, at a redemption price up to 103.063% of the principal amount, plus any accrued and unpaid interest; and, • Subject to repurchase upon the occurrence of a change in control repurchase event (as defined in the indenture) at a repurchase price in cash equal to 101% of the aggregate principal amount of the notes repurchased, plus any accrued and unpaid interest. The Company used the net proceeds of the 2028 Notes, together with cash on hand, to make discretionary contributions to certain U.S. defined benefit pension plans. The indentures governing the 2027 Notes, 2028 Notes, and 2029 Notes contain customary affirmative and negative covenants, such as limitations on liens, limitations on sale and leaseback transactions, and a prohibition on a reduction in the ownership of AWAC entities below an agreed level. The negative covenants in the indentures are less extensive than those in the Revolving Credit Facility (see below). For example, the indentures do not include a limitation on restricted payments, such as repurchases of common stock and dividends to stockholders. The 2027 Notes, the 2028 Notes, and the 2029 Notes are senior unsecured obligations of ANHBV and do not entitle the holders to any registration rights pursuant to a registration rights agreement. ANHBV does not intend to file a registration statement with respect to resales of or an exchange offer for the notes. The notes are guaranteed on a senior unsecured basis by Alcoa Corporation and its subsidiaries that are guarantors under the Facility (the “subsidiary guarantors” and, together with Alcoa Corporation, the “guarantors”). Each of the subsidiary guarantors will be released from their guarantees upon the occurrence of certain events, including the release of such guarantor from its obligations as a guarantor under the Facility. The 2027 Notes, the 2028 Notes, and the 2029 Notes rank equally in right of payment with each other and with all of ANHBV’S existing and future senior unsecured indebtedness; rank senior in right of payment to any future subordinated obligations of ANHBV; and are effectively subordinated to ANHBV’s existing and future secured indebtedness, including under the Facility, to the extent of the value of property and assets securing such indebtedness. The guarantees of the notes rank equally in right of payment with each other and with all the guarantors’ existing and future senior unsecured indebtedness; rank senior in right of payment to any future subordinated obligations of the guarantors; and are effectively subordinated to the guarantors’ existing and future secured indebtedness, including under the Facility, to the extent of the value of property and assets securing such indebtedness. Redemption events. On April 7, 2021, the Company redeemed in full $750 aggregate principal amount notes due in 2024 at a redemption price equal to 103.375% of the principal amount, plus accrued and unpaid interest. The issuance of the 2029 Notes and this redemption were determined to be an issuance of new debt and an extinguishment of existing debt. As a result, the Company recorded a loss of $32 on the extinguishment of debt in the second quarter of 2021 in Interest expense, which was comprised of the redemption premium and the write-off of deferred financing fees and unamortized debt issuance costs. The cash flows related to the transaction were classified as financing cash flows. On September 30, 2021, the Company redeemed in full $500 aggregate principal amount notes due in 2026 at a redemption price equal to 103.5% of the principal amount, plus accrued and unpaid interest. As a result, the Company recorded a loss of $22 on the extinguishment of debt in the third quarter of 2021 in Interest expense, which was comprised of the redemption premium and the write-off of deferred financing fees and unamortized debt issuance costs. The cash flows related to the transaction were classified as financing cash flows. Credit Facilities. Revolving Credit Facility On June 27, 2022, Alcoa Corporation and Alcoa Nederland Holding B.V. (ANHBV), a wholly owned subsidiary of Alcoa Corporation and the borrower, entered into an amendment and restatement agreement (the Third Amendment and Restatement) (as amended and restated, the Revolving Credit Facility) that provided additional flexibility to the Company and ANHBV by (i) extending the maturity date of the Revolving Credit Facility from November 2023 to June 2027, (ii) reducing the aggregate commitments under the facility from $1,500 to $1,250, (iii) releasing the collateral package that had previously secured the Revolving Credit Facility, which would have continued so long as certain credit ratings were maintained, (iv) increasing the maximum leverage ratio from 2.75 to 1.00 to 3.25 to 1.00, which increased following material acquisitions for four consecutive fiscal quarters following an acquisition, (v) providing a debt to capitalization ratio not to exceed .60 to 1.00 to replace the maximum leverage ratio upon a ratings upgrade to investment grade by Moody’s Investor Service (Moody’s) or Standard and Poor’s Global Ratings (S&P), and (vi) providing flexibility for dividends and other restricted payments, to make investments, and to incur additional indebtedness. The Revolving Credit Facility implemented a sustainability adjustment to the applicable margin and commitment fee that may result in a positive or negative adjustment based on two of the Company’s existing sustainability metrics. On July 26, 2022, Moody’s upgraded the rating of ANHBV’s senior unsecured notes to Baa3 (investment grade). In addition to the financial covenants, the Revolving Credit Facility includes several customary affirmative and negative covenants (applicable to Alcoa Corporation and certain subsidiaries described as restricted), that, subject to certain exceptions, include limitations on (among other things): indebtedness, liens, investments, sales of assets, restricted payments, entering into restrictive agreements, a covenant prohibiting reductions in the ownership of AWAC entities, and certain other specified restricted subsidiaries of Alcoa Corporation, below an agreed level. The Revolving Credit Facility also contains customary events of default, including failure to make payments under the Revolving Credit Facility, cross-default and cross-judgment default, and certain bankruptcy and insolvency events. As of December 31, 2023, the Company was in compliance with all financial covenants. The Company may access the entire amount of commitments under the Revolving Credit Facility. There were no borrowings outstanding at December 31, 2023 and 2022, and no amounts were borrowed during 2023 and 2022 under the Revolving Credit Facility. On January 17, 2024, Alcoa Corporation, ANHBV, and certain subsidiaries of the Company entered into Amendment No. 1 (Amendment No. 1) to the Revolving Credit Facility (Amended Revolving Credit Facility). The Amended Revolving Credit Facility provides additional flexibility to the Company and the Borrower by temporarily (i) reducing the minimum interest coverage ratio required thereunder from 4.00 to 1.00 to 3.00 to 1.00 and (ii) providing for a maximum addback for cash restructuring charges in Consolidated EBITDA (as defined in the Revolving Credit Facility) of $450, in each case for the 2024 fiscal year. As of January 1, 2025, the minimum interest coverage ratio requirement will revert to 4.00 to 1.00 and the maximum addback for cash restructuring charges in Consolidated EBITDA will revert to 15% of Consolidated EBITDA. The requirement that the Company maintain a debt to capitalization ratio not to exceed .60 to 1.00 was not changed by Amendment No. 1. In connection with Amendment No. 1, the Company also agreed to provide collateral for its obligations under the Amended Revolving Credit Facility, which will require it to execute all security documents to re-secure collateral under the Amended Revolving Credit Facility by, subject to certain exceptions, a first priority security interest in substantially all assets of the Company, the Borrower, the material domestic wholly-owned subsidiaries of the Company, and the material foreign wholly-owned subsidiaries of the Company located in Australia, Brazil, Canada, Luxembourg, the Netherlands, Norway, and Switzerland including equity interests of certain subsidiaries that directly hold equity interests in AWAC entities. The collateral would be released if, on or after January 1, 2025, the Company or the Borrower (as applicable) (i) has at least two of the following three designated ratings: (x) Baa3 from Moody’s, (y) BBB- from S&P and (z) BBB- from Fitch Ratings and (ii) does not have any designated rating lower than: (x) Ba1 from Moody’s, (y) BB+ from S&P and (z) BB+ from Fitch Ratings. The Amended Revolving Credit Facility contains customary affirmative covenants, negative covenants, and events of default substantially comparable to the Revolving Credit Facility (other than those that are described above and other minor changes). The representations, warranties and covenants contained in the Amended Revolving Credit Facility were made only for purposes of Amendment No. 1 and as of specific dates and were solely for the benefit of the parties to the Amended Revolving Credit Facility. Japanese Yen Revolving Credit Facility In April 2023, the Company entered into a one-year unsecured revolving credit facility for $250 (available to be drawn in Japanese yen) (the Japanese Yen Revolving Credit Facility). Subject to the terms and conditions under the facility, the Company or ANHBV may borrow funds. The facility included covenants that are substantially the same as those included in the Revolving Credit Facility. As of December 31, 2023, the Company was in compliance with all financial covenants. The Company may access the entire amount of commitments under the facility. There were no borrowings outstanding at December 31, 2023 and $10 was borrowed and subsequently repaid in 2023. On January 17, 2024, Alcoa Corporation and ANHBV, entered into Amendment No. 1 to the Japanese Yen Revolving Credit Facility (Amended Japanese Yen Revolving Credit Facility) which contains changes that are substantially the same as those included in the Amended Revolving Credit Facility (as described above). Also in connection with this amendment, the Company agreed to provide collateral for its obligations with the same conditions as the Amended Revolving Credit Facility. On January 24, 2024, ANHBV drew $201 against this facility. |
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| Preferred and Common Stock | N. Preferred and Common Stock Preferred Stock. Alcoa Corporation is authorized to issue 100,000,000 shares of preferred stock at a par value of $0.01 per share. At December 31, 2023 and 2022, the Company had no issued preferred stock. Common Stock. Alcoa Corporation is authorized to issue 750,000,000 shares of common stock at a par value of $0.01 per share. As of December 31, 2023 and 2022, Alcoa Corporation had 178,472,464 and 176,969,091, respectively, issued and outstanding shares of common stock. Under its employee stock-based compensation plan, the Company issued shares of 1,503,373 in 2023, 1,434,543 in 2022, and 1,305,979 in 2021. The Company issues new shares to satisfy the exercise of stock options and the conversion of stock units. As of December 31, 2023, 20,525,431 shares of common stock were available for issuance. Common Stock Repurchase In October 2021, Alcoa Corporation’s Board of Directors approved a common stock repurchase program under which the Company may purchase shares of its outstanding common stock up to an aggregate transactional value of $500, depending on cash availability, market conditions, and other factors. In July 2022, Alcoa Corporation announced that its Board of Directors approved an additional common stock repurchase program under which the Company may purchase shares of its outstanding common stock up to an aggregate transactional value of $500, depending on the Company’s continuing analysis of market, financial, and other factors (the New Repurchase Program). No shares were repurchased in 2023. As of the date of this report, the Company is currently authorized to repurchase up to a total of $500, in the aggregate, of its outstanding shares of common stock under the New Repurchase Program. Repurchases under this program may be made using a variety of methods, which may include open market purchases, privately negotiated transactions, or pursuant to a Rule 10b5-1 plan. This program may be suspended or discontinued at any time and does not have a predetermined expiration date. Alcoa Corporation intends to retire repurchased shares of common stock. In 2022, the Company repurchased 8,565,200 shares of its common stock for $500, which fully exhausted the October 2021 authorization; the shares were immediately retired. In 2021, the Company repurchased 3,184,300 shares of its common stock for $150; the shares were immediately retired. Dividend Dividends on common stock are subject to authorization by Alcoa Corporation’s Board of Directors. In , the Company announced the initiation of a quarterly cash dividend on its common stock and the Board of Directors declared the first quarterly cash dividend of $0.10 per share of the Company’s common stock. Dividends paid totaled $19 in 2021. Quarterly dividends paid were $0.10 per share in 2023 and 2022, totaling $72 in both years. The details of any future cash dividend declaration, including the amount of such dividend and the timing and establishment of the record and payment dates, will be determined by the Board of Directors. The decision of whether to pay future cash dividends and the amount of any such dividends will be based on the Company's financial position, results of operations, cash flows, capital requirements, business conditions, the requirements of applicable law, and any other factors the Board of Directors may deem relevant. Stock-based Compensation Restricted stock units are generally granted in January and/or February of each calendar year to eligible employees (the Company’s Board of Directors also receive certain stock units; however, these amounts are not material). Time-based restricted stock units (RSUs) generally cliff vest on the third anniversary of the award grant date. The Company also grants performance restricted stock units (PRSUs), which are subject to performance conditions and earned after the end of the three-year measurement period. As of January 1, 2021, the Company no longer grants stock options. The final number of PRSUs earned is dependent on Alcoa Corporation’s achievement of certain targets over a three-year measurement period for grants. For PRSUs granted in 2021, the award was earned after the end of the measurement period of January 1, 2021 through December 31, 2023 based on performance against four measures: (1) the Company’s total shareholder return measured against the ranked total shareholder return of the Standard & Poor’s Metals and Mining Select Industry Index components; (2) a pre-established return-on-equity target; (3) an improvement in proportional net debt; and (4) a reduction in carbon intensity in both refining (through reduced carbon dioxide emissions) and smelting (through increased production from renewable energy) operations. For PRSUs granted in 2022, the award will be earned after the end of the measurement period of January 1, 2022 through December 31, 2024 based on performance against three measures: (1) the Company’s total shareholder return measured against the ranked total shareholder return of the Standard & Poor’s Metals and Mining Select Industry Index components; (2) a pre-established return-on-equity target; and (3) a reduction in carbon intensity in both refining (through reduced carbon dioxide emissions) and smelting (through increased production from renewable energy) operations. For PRSUs granted in 2023, the award will be earned after the end of the measurement period of January 1, 2023 through December 31, 2025 based on performance against three measures: (1) the Company’s total shareholder return measured against the ranked total shareholder return of the Standard & Poor’s Metals and Mining Select Industry Index components; (2) a pre-established return-on-equity target; and (3) a reduction in carbon intensity in both refining (through reduced carbon dioxide emissions) and smelting (through increased production from renewable energy) operations. In 2023, 2022, and 2021, Alcoa Corporation recognized stock-based compensation expense of $35, $40, and $39, respectively, of which approximately 95% to 100% was related to stock units in each period. There was no stock-based compensation expense capitalized in 2023, 2022, and 2021. Stock-based compensation expense is based on the grant date fair value of the applicable equity grant. For both RSUs and PRSUs, the fair value was equivalent to the closing market price per share of Alcoa Corporation’s common stock on the date of grant in the respective periods. For stock units with a market condition, the fair value was estimated on the date of grant using a Monte Carlo simulation model, which generated a result of $71.12, $126.86, and $39.88 per unit in 2023, 2022, and 2021, respectively. The Monte Carlo simulation model uses certain assumptions to estimate the fair value of a market-based stock unit, including volatility and a risk-free interest rate, to estimate the probability of satisfying market conditions. Volatility (64.88%, 65.25%, and 60.19% in 2023, 2022, and 2021, respectively) was estimated using the historical volatility of the Company calculated from daily stock price returns. The risk-free interest rate (4.26%, 1.71%, and 0.22% in 2023, 2022, and 2021, respectively) was based on the U.S. Treasury yield curve at the time of the grant based on the remaining performance period. The activity for stock units and stock options during 2023 was as follows:
The number of Converted units includes 657,448 shares withheld to meet the Company’s statutory tax withholding requirements related to the income earned by the employees as a result of vesting in the units. As of December 31, 2023, the 148,608 outstanding stock options were fully vested and exercisable, had a weighted average remaining contractual life of 3.99 years, a total intrinsic value of $2 and a weighted average exercise price of $26.73. Cash received from stock option exercises was $1, $22, and $25 in 2023, 2022, and 2021, respectively. The total intrinsic value of stock options exercised during 2023, 2022, and 2021 was $2, $22, and $17, respectively. The total fair value of stock units converted during 2023, 2022, and 2021 was $35, $32 and $19, respectively. At December 31, 2023, there was $23 of combined unrecognized compensation expense (pretax) related to non-vested grants of stock units. This expense is expected to be recognized over a weighted average period of 1.80 years. |
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Pension and Other Postretirement Benefits |
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| Retirement Benefits [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Pension and Other Postretirement Benefits | O. Pension and Other Postretirement Benefits Defined Benefit Plans Alcoa sponsors several defined benefit pension plans covering certain employees in the U.S. and foreign locations. Pension benefits generally depend on length of service, job grade, and remuneration. Substantially all benefits are paid through pension trusts that are sufficiently funded to ensure that all plans can pay benefits to retirees as they become due. Most salaried and non-bargaining hourly U.S. employees hired after March 1, 2006 and most bargaining hourly U.S. employees hired after January 1, 2020 participate in a defined contribution plan instead of a defined benefit plan. The Company also maintains health care postretirement benefit plans covering certain eligible U.S. retired employees and certain retirees from foreign locations. Generally, the medical plans are unfunded and pay a percentage of medical expenses, reduced by deductibles and other coverage. The Company retains the right, subject to existing agreements, to change or eliminate these benefits. All salaried and certain non-bargaining hourly U.S. employees hired after January 1, 2002 and certain bargaining hourly U.S. employees hired after July 1, 2010 are not eligible for postretirement health care benefits. As of January 1, 2023, the pension benefit plans and the other postretirement benefit plans covered an aggregate of approximately 17,000 and approximately 21,000 participants, respectively. 2023 Plan Actions. In 2023, management initiated the following actions to certain pension plans: Action #1 – In the second quarter of 2023, plan amendment accounting and related plan remeasurements were triggered within the Surinamese pension and other postretirement plans as a result of participants electing to prospectively convert their Surinamese dollar pension and Company-provided retiree medical to a United States dollar pension with no Company-provided retiree medical. As a result, Alcoa recorded a $15 increase to Accrued pension benefits and a $9 decrease to Accrued other postretirement benefits. Action #2 – In the second quarter of 2023, settlement accounting and related plan remeasurements were triggered within certain Canadian pension plans as a result of the Company's purchase of group annuity contracts to transfer the obligation to pay the remaining retirement benefits of approximately 530 retirees and beneficiaries from its Canadian defined benefit pension plans. The transfer of approximately $235 in both plan obligations and plan assets was completed in April 2023. As a result, Alcoa recorded a $22 increase to Accrued pension benefits and a $5 decrease to Other noncurrent assets and recognized a non-cash settlement loss of $21 ($16 after-tax) in Restructuring and other charges, net on the accompanying Statement of Consolidated Operations. Action #3 – In the third quarter of 2023, settlement accounting and a related plan remeasurement was triggered within Alcoa’s Australian pension plan as a result of participants electing lump sum payments. As a result, Alcoa recorded a $2 decrease to Other noncurrent assets. The following table presents certain information and the financial impacts of these actions on the accompanying Consolidated Financial Statements:
(1) This amount represents the net actuarial loss and was reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations. 2022 Plan Actions. In 2022, management initiated the following actions to certain pension and other postretirement benefit plans: Action #1 – In the third quarter of 2022, settlement accounting and related plan remeasurements were triggered within Alcoa’s U.S. pension plans as a result of the Company’s purchase of group annuity contracts to transfer the obligation to pay the remaining retirement benefits of approximately 4,400 retirees and beneficiaries from its U.S. defined benefit pension plans. The transfer of approximately $1,000 in both plan obligations and plan assets was completed in August 2022. As a result, Alcoa recorded a $5 increase to Accrued pension benefits and a $27 increase to Other noncurrent assets and recognized a non-cash settlement loss of $617 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations. Action #2 – In the third quarter of 2022, settlement accounting and related plan remeasurements were triggered within Alcoa’s U.S. pension plans as a result of participants electing lump sum payments. Alcoa recognized a non-cash settlement loss of $11 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations. Action #3 – In the third quarter of 2022, settlement accounting and a related plan remeasurement was triggered within Alcoa’s U.S. salaried pension plan as a result of participants electing lump sum payments. Alcoa recorded a $23 increase to Accrued pension benefits and a $12 decrease to Other noncurrent assets and recognized a non-cash settlement loss of $1 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations. Action #4 – In the third quarter of 2022, settlement accounting and a related plan remeasurement was triggered within Alcoa’s Australian pension plan as a result of participants electing lump sum payments. Alcoa recorded a $21 increase to Other noncurrent assets and recognized a non-cash settlement gain of $3 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations. Action #5 – In the fourth quarter of 2022, settlement accounting was triggered within Alcoa’s U.S. pension plans as a result of participants electing lump sum payments. Alcoa recorded a $3 increase to Accrued pension benefits and recognized a non-cash settlement loss of $6 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations. The following table presents certain information and the financial impacts of these actions on the accompanying Consolidated Financial Statements:
(1) Actions 1-4 caused interim plan remeasurements, including an update to the discount rates used to determine the benefit obligations of the affected plans. These amounts include impacts due to interim plan remeasurements. (2) These amounts represent the net actuarial loss (gain) and were reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations. 2021 Plan Actions. In 2021, management initiated the following actions to certain pension and other postretirement benefit plans: Action #1 – On March 31, 2021, Alcoa completed the sale of the Warrick Rolling Mill to Kaiser Aluminum Corporation for total consideration of $670, which included the assumption of $69 in other postretirement benefit liabilities. Approximately 1,150 employees at the rolling operations, which includes the casthouse, hot mill, cold mills, and coating and slitting lines, became employees of Kaiser. As a result, the affected plan was remeasured, including an update to the discount rate used to determine the benefit obligation of the plan. Accrued other postretirement benefits reflects a decrease of $40 related to the remeasurement in addition to the $69 assumed by Kaiser. Further, Alcoa recognized a curtailment gain of $17 (pre- and after-tax) and a settlement loss of $26 (pre- and after-tax).
Action #2 – In the second quarter of 2021, settlement accounting and a related plan remeasurement was triggered within Alcoa’s U.S. salaried pension plan as a result of a high number of participants electing lump sum payments. This includes former employees of the Warrick Rolling Mill, as well as other Alcoa employees making this election at retirement. Alcoa recorded a $90 decrease to Accrued pension benefits related to this remeasurement and recognized a settlement loss of $39 (pre- and after-tax). Action #3 – In the third quarter of 2021, settlement accounting and a related plan remeasurement was triggered within Alcoa’s U.S. salaried pension plan as a result of participants electing lump sum payments. Alcoa recorded a $7 increase to Accrued pension benefits related to this remeasurement and recognized a settlement loss of $7 (pre- and after-tax). Action #4 – In the third quarter of 2021, settlement accounting and a related plan remeasurement was triggered within Alcoa’s Australian pension plan as a result of participants electing lump sum payments. Alcoa recorded a $38 decrease to Accrued pension benefits related to this remeasurement and recognized a settlement loss of $1 (pre- and after-tax). Action #5 – In the fourth quarter of 2021, the Company purchased a group annuity contract to transfer the obligation to pay the remaining retirement benefits of approximately 800 retirees and deferred vested participants from one of its Suriname pension plans to an insurance company. The transfer of $55 in both plan obligations and plan assets were completed on October 19, 2021. As a result, the Company recorded a settlement loss of $63 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations in the fourth quarter of 2021. Action #6 – In the fourth quarter of 2021, settlement accounting and related plan remeasurements were triggered within Alcoa’s U.S. pension plans as a result of the Company purchasing group annuity contracts to transfer the obligation to pay remaining retirement benefits of approximately 14,000 retirees and beneficiaries from its U.S. defined benefit pension plans and transferred approximately $1,540 in both plan obligations and plan assets. The transfers were completed on November 23, 2021 and December 16, 2021. As a result, the Company recorded a $84 decrease to Accrued pension benefits related to this remeasurement and recognized a non-cash settlement loss of $848 (pre- and after-tax) in Restructuring and other charges, net on the Statement of Consolidated Operations in the fourth quarter of 2021. Action #7 – In the fourth quarter of 2021, settlement accounting and related plan remeasurements were triggered within Alcoa’s U.S. pension plans as a result of participants electing lump sum payments (and the group annuity contracts discussed in Action 6 above). Alcoa recorded a $1 decrease to Accrued pension benefits related to this remeasurement and recognized a settlement loss of $10 (pre- and after-tax). The following table presents certain information and the financial impacts of these actions on the accompanying Consolidated Financial Statements:
(1) These amounts primarily represent the accelerated amortization of a portion of the existing prior service benefit for curtailments and net actuarial loss for settlements and were reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations.
Obligations and Funded Status
At December 31, 2023, the benefit obligation, fair value of plan assets, and funded status for U.S. pension plans were $1,119, $1,054, and ($65), respectively. At December 31, 2022, the benefit obligation, fair value of plan assets, and funded status for U.S. pension plans were $1,113, $1,064, and ($49), respectively. Pension Plan Benefit Obligations
Components of Net Periodic Benefit Cost
(1) In 2023, 2022, and 2021, net periodic benefit cost for U.S pension plans was $6, $698, and $962, respectively. (2) These amounts were reported in Other expenses (income), net on the accompanying Statement of Consolidated Operations. (3) These amounts were reported in Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note D). In 2023, 2022 and 2021, settlements were due to management actions (see Plan Actions above). (4) These amounts were reported in Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note D). In 2021, curtailments were due to management actions (see Plan Actions above). (5) Amounts attributed to joint venture partners are not included. Assumptions. Liabilities and expenses for pension and other postretirement benefits are determined using actuarial methodologies and incorporate significant assumptions, including the interest rate used to discount the future estimated liability, the expected long-term rate of return on plan assets, and several assumptions relating to the employee workforce (salary increases, health care cost trend rates, retirement age, and mortality). Weighted average assumptions used to determine benefit obligations for pension and other postretirement benefit plans were as follows:
The yield curve model used to develop the discount rate parallels the plans’ projected cash flows and has a weighted average duration of 10 years. The underlying cash flows of the high-quality corporate bonds included in the model exceed the cash flows needed to satisfy the Company’s plan obligations multiple times. If a deep market of high-quality corporate bonds does not exist in a country, then the yield on government bonds plus a corporate bond yield spread is used. Weighted average assumptions used to determine net periodic benefit cost for pension and other postretirement benefit plans were as follows:
For 2023, 2022, and 2021, the expected long-term rate of return used by management was based on the prevailing and planned strategic asset allocations, as well as estimates of future returns by asset class. For 2024, management anticipates that 6.13% will be the weighted average expected long-term rate of return. Assumed health care cost trend rates for U.S. other postretirement benefit plans were as follows (non-U.S. plans are not material):
The assumed health care cost trend rate is used to measure the expected cost of gross eligible charges covered by the Company’s other postretirement benefit plans. For 2024, a 6.5% trend rate will be used, reflecting management’s best estimate of the change in future health care costs covered by the plans. Plan Assets. Alcoa’s pension plan weighted average target and actual asset allocations at December 31, 2023 and 2022, by asset class, were as follows:
The principal objectives underlying the investment of the pension plan assets are to ensure that the Company can properly fund benefit obligations as they become due under a broad range of potential economic and financial scenarios, maximize the long-term investment return with an acceptable level of risk based on such obligations, and broadly diversify investments across and within various asset classes to protect asset values against adverse movements. Investment risk is controlled by rebalancing to target allocations on a periodic basis and ongoing monitoring of investment manager performance. The portfolio includes an allocation to investments in long-duration corporate credit and government debt, public and private market equities, intermediate duration corporate credit and government debt, global-listed infrastructure, high-yield bonds and bank loans, real estate, and securitized credit. In late 2022, management began restructuring the asset portfolios of certain non-U.S. pension plans. The new strategy increased the amount and duration of the fixed income asset portfolios to reduce exposure to interest rates and was substantially implemented at the end of the first quarter in 2023. Investment practices comply with the requirements of applicable laws and regulations in the respective jurisdictions, including the Employee Retirement Income Security Act of 1974 (ERISA) in the United States. The following section describes the valuation methodologies used by the trustees to measure the fair value of pension plan assets. For plan assets measured at net asset value, this refers to the net asset value of the investment on a per share basis (or its equivalent) as a practical expedient. Otherwise, an indication of the level in the fair value hierarchy in which each type of asset is generally classified is provided (see Note P for the definition of fair value and a description of the fair value hierarchy). Equities—These securities consist of: (i) direct investments in the stock of publicly traded U.S. and non-U.S. companies and are valued based on the closing price reported in an active market on which the individual securities are traded (generally classified in Level 1); (ii) the plans’ share of commingled funds that are invested in the stock of publicly traded companies and are valued at net asset value; and (iii) direct investments in long/short equity hedge funds and private equity (limited partnerships and venture capital partnerships) and are valued at net asset value. Fixed income—These securities consist of: (i) U.S. government debt and are generally valued using quoted prices (included in Level 1); (ii) cash and cash equivalents invested in publicly-traded funds and are valued based on the closing price reported in an active market on which the individual securities are traded (generally classified in Level 1); (iii) publicly traded U.S. and non-U.S. fixed interest obligations (principally corporate bonds and debentures) and are valued through consultation and evaluation with brokers in the institutional market using quoted prices and other observable market data (included in Level 2); and (iv) cash and cash equivalents invested in institutional funds and are valued at net asset value. Other investments—These investments include, among others: (i) real estate investment trusts valued based on the closing price reported in an active market on which the investments are traded (included in Level 1); (ii) the plans’ share of commingled funds that are invested in real estate partnerships and are valued at net asset value; (iii) direct investments in private real estate (includes limited partnerships) and are valued at net asset value; and (iv) absolute return strategy funds and are valued at net asset value. The fair value methods described above may not be indicative of net realizable value or reflective of future fair values. Additionally, while Alcoa believes the valuation methods used by the plans’ trustees are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. The following table presents the fair value of pension plan assets classified under either the appropriate level of the fair value hierarchy or net asset value:
(1) As of December 31, 2023, the total fair value of pension plan assets excludes a net receivable of $13, which primarily represents securities not yet settled plus interest and dividends earned on various investments. (2) As of December 31, 2022, the total fair value of pension plan assets excludes a net receivable of $8, which primarily represents securities not yet settled plus interest and dividends earned on various investments. Funding and Cash Flows. It is Alcoa’s policy to fund amounts for defined benefit pension plans sufficient to meet the minimum requirements set forth in applicable country benefits laws and tax laws, including ERISA for U.S. plans. From time to time, the Company contributes additional amounts as deemed appropriate. In 2023, 2022, and 2021, cash contributions to Alcoa’s defined benefit pension plans were $24, $17, and $579. During 2021, Alcoa made $500 in unscheduled contributions to certain U.S. defined benefit pension plans. The additional contributions were discretionary in nature and were funded with net proceeds from a March 2021 debt issuance (see Note M) plus available cash on hand. There were no discretionary contributions made in 2022 or 2023. Alcoa’s minimum required contribution to defined benefit pension plans in 2024 is estimated to be $60, of which approximately $40 is for U.S. plans. Under ERISA regulations, a plan sponsor that establishes a pre-funding balance by making discretionary contributions to a U.S. defined benefit pension plan may elect to apply all or a portion of this balance toward its minimum required contribution obligations to the related plan in future years. In 2024, management intends to make such election related to the Company’s U.S. plans. Benefit payments expected to be paid to pension and other postretirement benefit plan participants are as follows:
Defined Contribution Plans The Company sponsors savings and investment plans in several countries, primarily in Australia and the United States. In the United States, employees may contribute a portion of their compensation to the plans, and Alcoa matches a specified percentage of these contributions in equivalent form of the investments elected by the employee. Also, the Company makes contributions to a retirement savings account based on a percentage of eligible compensation for certain U.S. employees that are not able to participate in Alcoa’s defined benefit pension plans. The Company’s expenses related to all defined contribution plans were $80 in 2023, $71 in 2022, and $72 in 2021. Member-funded Pension Plans The Company contributes to member-funded pension plans for the employees of Aluminerie de Bécancour Inc. and Aluminerie de Deschambault in Canada. Alcoa makes contributions to the plans based on a percentage of the employees’ eligible compensation. The Company’s expenses related to the member-funded pension plans were $16 in 2023, $17 in 2022, and $17 in 2021. Target Benefit Plan The Company contributes to a target benefit plan for the employees of Baie-Comeau in Canada. Alcoa makes contributions to the plan based on a percentage of the employees’ eligible compensation. The Company’s expenses related to the target benefit plan were $8 in 2023, $9 in 2022, and $9 in 2021. |
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Derivatives and Other Financial Instruments |
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| Fair Value Disclosures [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Derivatives and Other Financial Instruments | P. Derivatives and Other Financial Instruments Fair Value. The Company follows a fair value hierarchy to measure its assets and liabilities. As of December 31, 2023 and 2022, respectively, the assets and liabilities measured at fair value on a recurring basis were primarily derivative instruments. In addition, the Company measures its pension plan assets at fair value (see Note O). Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy distinguishes between (i) market participant assumptions developed based on market data obtained from independent sources (observable inputs) and (ii) an entity’s own assumptions about market participant assumptions developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy are described below: • Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; • Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates); and inputs that are derived principally from or corroborated by observable market data by correlation or other means; and, • Level 3—Inputs that are both significant to the fair value measurement and unobservable. Derivatives. Alcoa Corporation is exposed to certain risks relating to its ongoing business operations, including the risks of changing commodity prices, foreign currency exchange rates and interest rates. Alcoa Corporation’s commodity and derivative activities include aluminum, energy, foreign exchange, and interest rate contracts, which are held for purposes other than trading. They are used to mitigate uncertainty and volatility, and to cover underlying exposures. While Alcoa does not generally enter into derivative contracts to mitigate the risk associated with changes in aluminum price, the Company may do so in isolated cases to address discrete commercial or operational conditions. Alcoa is not involved in trading activities for energy, weather derivatives, or other nonexchange commodities. Alcoa Corporation’s commodity and derivative activities are subject to the management, direction, and control of the Strategic Risk Management Committee (SRMC), which consists of at least three members, including the chief executive officer, the chief financial officer, and the chief commercial officer. The remaining member(s) are other officers and/or employees of the Company as the chief executive officer may designate from time to time. The SRMC meets on a periodic basis to review derivative positions and strategy and reports to the Audit Committee of Alcoa Corporation’s Board of Directors on the scope of its activities. Alcoa Corporation’s aluminum and foreign exchange contracts are predominately classified as Level 1 under the fair value hierarchy. All of the Level 1 contracts are designated as either fair value or cash flow hedging instruments (except as described below). Alcoa Corporation also has several derivative instruments classified as Level 3 under the fair value hierarchy, which are either designated as cash flow hedges or undesignated. Alcoa includes the changes in its equity method investee’s Level 2 derivatives in Accumulated other comprehensive loss. The following tables present the detail for Level 1 and 3 derivatives (see additional Level 3 information in further tables below):
The 2023 realized gain of $86 on Level 1 cash flow hedges was comprised of a $91 gain recognized in Sales and a $5 loss recognized in Cost of goods sold. The 2022 realized gain of $35 on Level 1 cash flow hedges was comprised of a $40 gain recognized in Sales and a $5 loss recognized in Cost of goods sold. The following table presents the outstanding quantities of derivative instruments classified as Level 1:
Alcoa routinely uses Level 1 aluminum derivative instruments to manage exposures to changes in the fair value of firm commitments for the purchases or sales of aluminum. Additionally, Alcoa uses Level 1 aluminum derivative instruments to manage exposures to changes in the LME associated with the Alumar (Brazil) restart ( through December 2023) and the San Ciprián (Spain) strike (expired October 2022). As a result of delays with the Alumar restart, it became probable that certain of the original forecasted transactions would not occur by the end of the originally specified time period and Alcoa dedesignated certain aluminum sell forwards. The Company reclassified the related unrealized gain of $11 and $20 included in Accumulated other comprehensive loss to Sales during the year ended December 31, 2023 and 2022, respectively. In conjunction with the dedesignations, the Company entered into aluminum buy forwards in 2023 and 2022 for the same volume and periods which were also not designated. The unrealized and realized gains and losses on the aluminum buy and sell forwards that are not designated offset resulting in no impact to Alcoa’s earnings. Alcoa Corporation uses Level 1 foreign exchange forward contracts to mitigate the risk of foreign exchange exposure related to euro power purchases in Norway (expires December 2026), U.S. dollar aluminum sales in Norway (expires June 2025), U.S. dollar alumina and aluminum sales in Brazil (expires August 2025), and U.S. dollar aluminum sales in Canada (expires March 2025). Derivative instruments classified as Level 3 in the fair value hierarchy represent those in which management has used at least one significant unobservable input in the valuation model. Alcoa Corporation uses a discounted cash flow model to fair value all Level 3 derivative instruments. Inputs in the valuation models for Level 3 derivative instruments are composed of the following: (i) quoted market prices (e.g., aluminum prices on the 10-year LME forward curve and energy prices), (ii) significant other observable inputs (e.g., information concerning time premiums and volatilities for certain option type embedded derivatives and regional premiums for aluminum contracts), and (iii) unobservable inputs (e.g., aluminum and energy prices beyond those quoted in the market, and estimated credit spread between Alcoa and the counterparty). For periods beyond the term of quoted market prices for aluminum, Alcoa Corporation estimates the price of aluminum by extrapolating the 10-year LME forward curve. For periods beyond the term of quoted market prices for the Midwest premium, management estimates the Midwest premium based on recent transactions. Where appropriate, valuations are adjusted for various factors such as liquidity, bid/offer spreads, and credit considerations. Such adjustments are generally based on available market evidence (Level 2). In the absence of such evidence, management’s best estimate is used (Level 3). If a significant input that is unobservable in one period becomes observable in a subsequent period, the related asset or liability would be transferred to the appropriate classification (Level 1 or 2) in the period of such change (there were no such transfers in the periods presented). There were no sales or settlements of Level 3 derivative instruments in the periods presented. Level 3 derivative instruments outstanding as of December 31, 2023 are described in the table below:
In December 2022, Alcoa entered into a financial contract with a counterparty to hedge power price exposure through March 31, 2023. The Financial contract was designated as a cash flow hedge of future sales of power. Unrealized gains and losses were recognized in Accumulated other comprehensive loss on the accompanying Consolidated Balance Sheet, and realized gains and losses were recognized in Cost of goods sold on the accompanying Statement of Consolidated Operations. In addition to the instruments presented above, Alcoa had a financial contract that expired in July 2021 that hedged the anticipated power requirements at one of its smelters and was designated as a cash flow hedge of future purchases of electricity. In March 2021, Alcoa entered into four financial contracts (Financial contracts (undesignated), below) with three counterparties to hedge the anticipated power requirements at this smelter for the period from August 1, 2021 through June 30, 2026. A fifth financial contract (undesignated) was entered into in November 2021, with an effective date of September 30, 2022 through June 30, 2026. In August 2023, the Company entered into a nine-year financial contract (undesignated) effective July 1, 2026 when the current contracts end. Three of these financial contracts include LME-linked pricing components and do not qualify for hedge accounting treatment. Management elected not to apply hedge accounting treatment for the other three financial contracts. Unrealized and realized gains and losses on these financial contracts are included in Other expenses (income), net on the accompanying Statement of Consolidated Operations. At December 31, 2023, the outstanding Level 3 instruments are associated with seven smelters. At December 31, 2023 and 2022, the power contracts with embedded derivatives designated as cash flow hedges hedge forecasted aluminum sales of 1,456 kmt and 1,683 kmt, respectively. The following table presents quantitative information related to the significant unobservable inputs described above for Level 3 derivative instruments (megawatt hours in MWh):
The fair values of Level 3 derivative instruments recorded in the accompanying Consolidated Balance Sheet were as follows:
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:
The following tables present a reconciliation of activity for Level 3 derivative instruments:
Derivatives Designated As Hedging Instruments—Cash Flow Hedges Assuming market rates remain constant with the rates at December 31, 2023, a realized loss of $210 related to power contracts is expected to be recognized in Sales over the next 12 months. Material Limitations The disclosures with respect to commodity prices and foreign currency exchange risk do not consider the underlying commitments or anticipated transactions. If the underlying items were included in the analysis, the gains or losses on the futures contracts may be offset. Actual results will be determined by several factors that are not under Alcoa Corporation’s control and could vary significantly from those factors disclosed. Alcoa Corporation is exposed to credit loss in the event of nonperformance by counterparties on the above instruments, as well as credit or performance risk with respect to its hedged customers’ commitments. Alcoa Corporation does not anticipate nonperformance by any of these parties. Contracts are with creditworthy counterparties and are further supported by cash, treasury bills, or irrevocable letters of credit issued by carefully chosen banks. In addition, various master netting arrangements are in place with counterparties to facilitate settlement of gains and losses on these contracts. Other Financial Instruments. The carrying values and fair values of Alcoa Corporation’s other financial instruments were as follows:
Cash and cash equivalents and Restricted cash. The carrying amounts approximate fair value because of the short maturity of the instruments. The fair value amounts for Cash and cash equivalents and Restricted cash were classified in Level 1 of the fair value hierarchy. Short-term borrowings and Long-term debt, including amounts due within one year. The fair value of Long-term debt, less amount due within one year was based on quoted market prices for public debt and on interest rates that are currently available to Alcoa Corporation for issuance of debt with similar terms and maturities for non-public debt. The fair value amounts for all Short-term borrowings and Long-term debt were classified in Level 2 of the fair value hierarchy. |
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Income Taxes |
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| Income Tax Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Income Taxes | Q. Income Taxes Provision for income taxes. The components of (Loss) income before income taxes were as follows:
Provision for income taxes consisted of the following:
Federal includes U.S. income taxes related to foreign income. A reconciliation of the U.S. federal statutory rate to Alcoa’s effective tax rate was as follows:
Certain income earned by AWAB is eligible for a tax holiday, which decreases the tax rate on this income from 34% to 15.25%, which will result in future cash tax savings. The holiday related to production at the Alumar refinery was originally expected to end on December 31, 2027. During 2023, it was extended to December 31, 2032. The holiday related to the operation of the Juruti (Brazil) bauxite mine will end on December 31, 2026. In 2021, it was determined that the deferred taxes associated with income subject to the tax holiday would be fully exhausted within the holiday period and the amounts were therefore maintained on the balance sheet at the holiday tax rate. In 2022, the Company’s projection of the reversal of deferred tax assets during the holiday tax period was lowered, and as a result, the remainder was revalued at the statutory rate of 34%, resulting in a discrete income tax benefit of $33, which is included in Tax holidays, above. In 2023, the Company determined that it was no longer more likely than not that the deferred tax asset at AWAB would be realized and recorded a full valuation allowance against the deferred tax asset (see below). As a result, the amount reflected in Tax holidays, above, is zero with respect to AWAB as of December 31, 2023. In October 2022, Alcoa completed the liquidation of Alcoa Saudi Rolling Inversiones S.L. (ASRI), a wholly owned subsidiary that previously held the Company’s investment in MRC. This liquidation resulted in a deductible loss in the Netherlands and a tax benefit of $94 was recognized in 2022, however, this tax benefit was substantially offset by a valuation allowance. In December 2022, Alcoa commenced an internal reorganization to reduce its number of legal entities in Norway from four to one to simplify accounting and treasury functions and reduce external costs. As a result of the simplification, the Company recorded a deferred tax expense of $30 in 2022. Deferred income taxes. The components of deferred tax assets and liabilities based on the underlying attributes without regard to jurisdiction were as follows:
The following table details the expiration periods of the deferred tax assets presented above:
Deferred tax assets with no expiration may still have annual limitations on utilization. Other represents deferred tax assets whose expiration is dependent upon the reversal of the underlying temporary difference. The total deferred tax asset (net of valuation allowance) is supported by projections of future taxable income exclusive of reversing temporary differences and taxable temporary differences that reverse within the carryforward period. The composition of Alcoa’s net deferred tax asset by jurisdiction as of December 31, 2023 was as follows:
The Company has several income tax filers in various foreign countries. Of the $147 net deferred tax asset included under the Foreign column in the table above, approximately 90% relates to six of Alcoa’s income tax filers (the Foreign Filers) as follows: a $135 net deferred tax asset for Alcoa Canada Company in Canada; a $90 net deferred tax asset for Alcoa-Lauralco Management Company in Canada; a $39 net deferred tax asset for Alcoa Wolinbec Company in Canada; a $19 net deferred tax asset for Alcoa Islandi and a $35 net deferred tax asset for Fjarðaál, both in Iceland; and a $185 net deferred tax liability for AofA in Australia. The future realization of the net deferred tax asset for each of the Foreign Filers was based on projections of the respective future taxable income (defined as the sum of pretax income, other comprehensive income, and permanent tax differences), exclusive of reversing temporary differences and carryforwards. The realization of the net deferred tax assets of the Foreign Filers is not dependent on any future tax planning strategies. Accordingly, management concluded that the net deferred tax assets of the Foreign Filers referenced above will more likely than not be realized in future periods, resulting in no need for a partial or full valuation allowance as of December 31, 2023. In December 2023, Alcoa recorded a valuation allowance of $154 against the net deferred tax assets of AWAB, of which $106 related to the balance as of December 31, 2022. The 2023 full valuation allowance for AWAB was a result of AWAB’s three-year cumulative loss position for the period ended December 31, 2023. The majority of AWAB’s net deferred tax assets relate to prior net operating losses; the loss carryforwards are not subject to an expiration period. AWAB’s profitability in future periods could prompt the Company to evaluate the realizability of the deferred tax asset and assess the possibility of a reversal of the valuation allowance, which could have a significant impact on net income in the quarter the valuation allowance is reversed. The Company’s subsidiaries in Iceland had a full valuation allowance recorded against deferred tax assets, which was established in 2015 and 2017, as the Company believed it was more likely than not that these tax benefits would not be realized. During 2023, after considering all positive and negative evidence, including the expectation that the jurisdiction will remain in a three-year cumulative income position, the Company determined that it is more likely than not that the net deferred tax assets will be realized. Based on this conclusion, the Company reversed the valuation allowance totaling $58 during 2023, generating a non-cash benefit from income taxes.
In December 2022, Alcoa recorded a valuation allowance of $217 against the net deferred tax assets of Alcoa Alumínio (Alumínio), of which $150 related to the balance as of December 31, 2021. The 2022 full valuation allowance for Alumínio was a result of Alumínio’s three-year cumulative loss position for the period ended December 31, 2022. Although the Company entered into aluminum contracts to manage exposures associated with the restart, these contracts were held by another legal entity, and the associated realized gains are not available to Alumínio to offset the restart losses. While management believes Alumínio will return to profitability in the future with the restart of the Alumar smelter, current volatility in the market does not provide a reliable basis for concluding that it is more likely than not that Alumínio’s net deferred tax assets, which consist primarily of tax loss carryforwards with indefinite life, will be realized. Alumar smelter profitability in future periods could prompt the Company to evaluate the realizability of the deferred tax asset and assess the possibility of a reversal of the valuation allowance, which could have a significant impact on net income in the quarter the valuation allowance is reversed. In 2021, Alcoa recorded a valuation allowance of $103 against the net deferred tax assets of Alúmina Española, S.A. (Española). Management concluded that it was more likely than not that Española’s net deferred tax assets, which consisted primarily of tax loss carryforwards, would not be realized as the entity’s sole operating asset, the San Ciprián refinery, was in a three-year cumulative loss position for the period ended December 31, 2021. This cumulative loss position was the result of recent operating losses due to the high energy costs in Spain and the impact of the refinery workers’ strike on the fourth quarter of 2021. After weighing all available positive and negative evidence as of December 31, 2023, management’s position continues to be that it is more likely than not that Alcoa Corporation will not realize the benefit of these deferred tax assets and continues to have a full valuation allowance recorded against the deferred tax assets. The following table details the changes in the valuation allowance:
(1) Reflects valuation allowances initially established as a result of a change in management’s judgment regarding the realizability of deferred tax assets. (2) Reflects movements in previously established valuation allowances, which increase or decrease as the related deferred tax assets increase or decrease. Such movements occur as a result of a change in management’s judgment regarding previously established valuation allowances, remeasurement due to a tax rate change and changes in the underlying attributes of the deferred tax assets, including expiration of the attribute and reversal of the temporary difference that gave rise to the deferred tax asset. Undistributed net earnings. Certain earnings of Alcoa’s foreign subsidiaries are deemed to be permanently reinvested outside the United States. The cumulative amount of Alcoa’s foreign undistributed net earnings deemed to be permanently reinvested was approximately $2,676 as of December 31, 2023. Alcoa Corporation has several commitments and obligations related to the Company’s operations in various foreign jurisdictions; therefore, management has no plans to distribute such earnings in the foreseeable future. Alcoa Corporation continuously evaluates its local and global cash needs for future business operations and anticipated debt facilities, which may influence future repatriation decisions. If these earnings were distributed in the form of dividends or otherwise, Alcoa could be subject to foreign income or withholding taxes and state income taxes. Due to the uncertainty of the manner in which the undistributed earnings would be brought back to the United States and the tax laws in effect at that time, it is not practicable to estimate the tax liability that might be incurred if such earnings were remitted to the U.S. Unrecognized tax benefits. Alcoa and its subsidiaries file income tax returns in the U.S. federal jurisdiction and various foreign and U.S. state jurisdictions. With few exceptions, the Company is not subject to income tax examinations by tax authorities for years prior to 2014. The U.S. federal income tax filings of the Company’s U.S. consolidated tax group have been examined through the 2018 tax year. Foreign jurisdiction tax authorities are in the process of examining income tax returns of several of Alcoa’s subsidiaries for various tax years. Excluding the Australia tax matter discussed in Note S, the period under foreign examination includes the income tax years from 2014 through 2022. For U.S. state income tax purposes, the Company and its subsidiaries remain subject to income tax examinations for the 2017 tax year and forward. In the third quarter of 2020, AofA paid approximately $74 (A$107) to the ATO related to the tax dispute described in Note S. Upon payment, AofA recorded a noncurrent prepaid tax asset, as the Company continues to believe it is more likely than not that AofA’s tax position will be sustained and therefore is not recognizing any tax expense in relation to this matter. In accordance with Australian tax laws, the initial interest assessment and additional interest are deductible against AofA’s taxable income. AofA applied this deduction beginning in the third quarter of 2020, reducing cash tax payments. Interest compounded in future years is also deductible against AofA’s income in future periods. If AofA is ultimately successful, the interest deduction would become taxable as income in the year the dispute is resolved. In addition, should the ATO decide in the interim to reduce any interest already assessed, the reduction would be taxable as income at that point in time. During 2023, AofA continued to record its tax provision and tax liability without effect of the ATO assessment, since it expects to prevail. The tax payable will remain on AofA’s balance sheet as a noncurrent liability, increased by the tax effect of subsequent periods’ interest deductions, until dispute resolution, which is expected to take several years. The noncurrent liability resulting from the cumulative interest deductions was approximately $199 (A$293) and $174 (A$260) at December 31, 2023 and 2022, respectively. The reserve balance for unrecognized tax benefits is included in Noncurrent income taxes on the Consolidated Balance Sheet. A reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding interest and penalties) was as follows:
For all periods presented, a portion of the balance at end of year pertains to state tax liabilities, which are presented before any offset for federal tax benefits. The effect of unrecognized tax benefits, if recorded, that would impact the annual effective tax rate for 2023, 2022, and 2021 would be 1%, 1%, and 0%, respectively, of (Loss) income before income taxes. Alcoa does not anticipate that changes in its unrecognized tax benefits will have a material impact on the Statement of Consolidated Operations during 2024. It is the Company’s policy to recognize interest and penalties related to income taxes as a component of the Provision for income taxes on the accompanying Statement of Consolidated Operations. In 2023, 2022, and 2021 Alcoa recognized $1, $1, and $0, in interest and penalties, respectively. Due to the expiration of the statute of limitations, settlements with tax authorities, and refunded overpayments, the Company also recognized interest income of $1, $1, and $0 in 2023, 2022, and 2021, respectively. As of December 31, 2023 and 2022, the amount accrued for the payment of interest and penalties was $4 and $3, respectively. Other Matters. On August 16, 2022, the U.S. enacted the Inflation Reduction Act of 2022 (IRA), which includes a 15% minimum tax on book income of certain large corporations, a 1% excise tax on net stock repurchases after December 31, 2022, and several tax incentives to promote clean energy. As a result of the provisions of the IRA, we will incur an excise tax of 1% for certain common stock repurchases made subsequent to December 31, 2022, which will be reflected in the cost of purchasing the underlying shares. The minimum corporate tax did not have an impact on the Company for 2023 and will not have an impact on the Company for 2024. The IRA contains a number of tax credits and other incentives for investments in renewable energy production, carbon capture, and other climate-related actions, as well as the production of critical minerals. In December 2023, the U.S. Treasury issued guidance on Section 45X of the Advanced Manufacturing Tax Credit. The Notice of Proposed Rulemaking (the Notice) clarifies that commercial grade aluminum can qualify for the credit, which was designed to incentivize domestic production of critical materials important for the transition to clean energy. In the fourth quarter of 2023, the Company recorded a benefit of $36 in Cost of goods sold and Other receivables related to its Massena West smelter (New York) and its Warrick smelter (Indiana). |
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Asset Retirement Obligations |
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Asset Retirement Obligation Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Asset Retirement Obligations | R. Asset Retirement Obligations The following table details the carrying value of recorded AROs by major category, of which $217 and $117 was classified as a current liability as of December 31, 2023 and 2022, respectively:
The following table details the changes in the total carrying value of recorded AROs:
Liabilities incurred in 2023 include: • $97 for changes in closure estimates of operating bauxite residue areas; • $87 for new mining areas opened during the year and higher estimated mine reclamation costs; • $36 related to the closure of the previously curtailed Intalco smelter; • $23 related to spent pot lining treatment and disposal; • $10 for changes in closure estimates of non-operating bauxite residue areas; and, • $1 related to an accrual for demolition for the closure of a potline at Warrick Operations. The additional accruals were primarily recorded with corresponding capitalized asset retirement costs except for $15 related to non-operating bauxite residue areas at the Alumar refinery, spent pot lining and treatment, and mine reclamation which was recorded to Cost of goods sold; and $41 related to the closure of the Intalco smelter, updated estimates for spent pot lining treatment and disposal at a previously closed site, and demolition accruals for the closure of a potline at Warrick Operations, which was recorded to Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note D). Liabilities incurred in 2022 include: • $81 related to improvements required on both operating and non-operating bauxite residue areas at the Poços de Caldas and Alumar refineries for changes in closure estimates and to comply with updated impoundment regulations in the regions; • $79 for new mining areas opened during the year and higher estimated mine reclamation costs; • $28 related to spent pot lining treatment and disposal; • $18 for bauxite residue areas related to water management at non-operating bauxite residue areas and changes in engineering designs for closure of operating bauxite residue areas; • $15 related to the closure of the previously curtailed magnesium smelter in Addy (Washington). The facility has been fully curtailed since 2001; and, • $3 related to accruals for demolition projects at closed sites. The additional accruals were primarily recorded with corresponding capitalized asset retirement costs (see Note B) except for $72 related to non-operating bauxite reside areas which was recorded to Cost of goods sold at the Poços de Caldas and Alumar refineries and $34 related to the closure of the magnesium smelter in Addy and adjustments to other previously closed sites which were recorded to Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note D). In 2023, reversals of previously recorded liabilities included a reversal of $8 due to changes in estimates at various sites and the completion of a site demolition project. In 2022, reversals of previously recorded liabilities included a reversal of $12 due to the completion of demolition projects at numerous permanently closed sites. The estimated timing of cash outflows for recorded AROs at December 31, 2023 was as follows:
Changes to the estimates may result in material changes to the recorded AROs that may require an increase to or a reversal of previously recorded liabilities, as well as changes in the timing of cash outflows. |
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Contingencies and Commitments |
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Commitments and Contingencies Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Contingencies and Commitments | S. Contingencies and Commitments Contingencies Environmental Matters Alcoa Corporation participates in environmental assessments and cleanups at several locations. These include currently or previously owned or operated facilities and adjoining properties, and waste sites, including Superfund (Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)) sites. Alcoa Corporation’s environmental remediation reserve balance reflects the most probable costs to remediate identified environmental conditions for which costs can be reasonably estimated. The following table details the changes in the carrying value of recorded environmental remediation reserves:
At December 31, 2023 and 2022, the current portion of the balance was $66 and $58, respectively. In 2023, the Company incurred liabilities of $39 primarily related to $14 for the closure of the previously curtailed Intalco smelter and $13 for an increase in estimated costs associated with ongoing remediation work at the previously closed Longview (Washington) site which were recorded in Restructuring and other charges, net on the Statement of Consolidated Operations, and $12 for an increase in estimated costs associated with ongoing remediation work at various other sites which was recorded in Cost of goods sold on the accompanying Statement of Consolidated Operations. Payments related to remediation expenses applied against the reserve were $55 in 2023. These amounts include mandated expenditures as well as those not required by any regulatory authority or third party. Further, the Company reversed reserves of $1 during 2023 due to the determination that certain remaining site remediation is no longer required. In 2022, the Company incurred liabilities of $32 primarily related to $14 for the closure of the previously curtailed magnesium smelter in Addy (Washington), $6 for estimates for environmental remediation at the Point Henry site, $4 for a new phase of work at the former East St. Louis site and $9 for environmental activities at various sites. These charges are recorded in Cost of goods sold and Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations. Payments related to remediation expenses applied against the reserve were $26 in 2022. These amounts include mandated expenditures as well as those not required by any regulatory authority or third party. Further, the Company reversed reserves of $30 during 2022, primarily related to changes in estimates for site remediation at Massena East of $18 and Suralco of $5, and completion of remediation at a previously closed site in Brazil of $6. In 2021, the Company incurred liabilities of $21 primarily related to remediation design considerations at the Longview site in Washington, closure of the Wenatchee aluminum smelter in Washington, environmental activities at the Point Comfort site in Texas, closure of the anode plant at the Lake Charles site in Louisiana, and wetlands mitigation at the Longview site in Washington, as well as other increases for ongoing monitoring and maintenance at various sites. These charges are primarily recorded in Cost of goods sold and Restructuring and other charges, net on the accompanying Statement of Consolidated Operations. Payments in 2021 include mandated expenditures as well as those not required by any regulatory authority or third-party. Further, the Company reversed reserves of $17 related to: • $7 due to the determination that previously estimated site remediation is not required at the previously closed Tennessee site; • $5 due to lower costs for waste treatment at a previously closed Suriname site; and, • $5 due to lower costs for site remediation related to a previously closed site in Brazil. The estimated timing of cash outflows from the environmental remediation reserve at December 31, 2023 was as follows:
Reserve balances at December 31, 2023 and 2022, associated with significant sites with active remediation underway or for future remediation were $211 and $234, respectively. In management’s judgment, the Company’s reserves are sufficient to satisfy the provisions of the respective action plans. Upon changes in facts or circumstances, a change to the reserve may be required. The Company’s significant sites include: Suriname—The reserve associated with the 2017 closure of the Suralco refinery and bauxite mine is for treatment and disposal of refinery waste and soil remediation. The work began in 2017 and is expected to be completed at the end of 2025. Hurricane Creek, Arkansas—The reserve associated with the 1990 closure of two mining areas and refineries near Hurricane Creek, Arkansas is for ongoing monitoring and maintenance for water quality surrounding the mine areas and residue disposal areas. Massena, New York—The reserve associated with the 2015 closure of the Massena East smelter by the Company’s subsidiary, Reynolds Metals Company, is for subsurface soil remediation to be performed after demolition of the structures. Remediation work commenced in 2021 and will take to eight years to complete. Point Comfort, Texas—The reserve associated with the 2019 closure of the Point Comfort alumina refinery is for disposal of industrial wastes contained at the site, subsurface remediation, and post-closure monitoring and maintenance. The final remediation plan is currently being developed, which may result in a change to the existing reserve. Sherwin, Texas—In connection with the 2018 settlement of a dispute related to the previously-owned Sherwin alumina refinery, the Company’s subsidiary, Copano Enterprises LLC, accepted responsibility for the final closure of four bauxite residue waste disposal areas (known as the Copano facility). Work commenced on the first residue disposal area in 2018 and is expected to take up to an additional four years to complete, depending on the nature of its potential re-use. Other than ongoing maintenance and repair activities, work on the next three areas has not commenced but is expected to be completed by 2048, depending on its potential re-use. Longview, Washington— In connection with a 2018 Consent Decree and Cleanup Action Plan with the State of Washington Department of Ecology, the Company’s subsidiary, Northwest Alloys as landowner, accepted certain responsibilities for future remediation of contaminated soil and sediments at the site located near Longview, Washington. In December 2020, the lessee of the land, who was a partner in the remediation of the site, filed for bankruptcy and exited the site in January 2021. The full site remediation project design, long-term and post-closure monitoring and maintenance at the site was approved in March 2023. In the third quarter of 2023, changes in scope and cost increases for remediation resulted in an increase to the reserve. The project is planned to be completed in the next two years. Addy, Washington—The reserve associated with the 2022 closure of the Addy magnesium smelter facility is for site-wide remediation and investigation and post-closure monitoring and maintenance. Remediation work is not expected to begin until 2026 and will take to five years to complete. The final remediation plan is currently being developed, which may result in a change to the existing reserve. Ferndale, Washington—The reserve associated with the 2023 closure of the Intalco aluminum smelter in Ferndale, Washington is for below grade site remediation and five years of post-closure maintenance and monitoring. The final remediation plan is under review.
Other Sites—The Company is in the process of decommissioning various other plants and remediating sites in several countries for potential redevelopment or to return the land to a natural state. In aggregate, there are remediation projects at 32 other sites that are planned or underway. These activities will be completed at various times in the future with the latest expected to be in 2026, after which ongoing monitoring and other activities may be required. At December 31, 2023 and 2022, the reserve balance associated with these activities was $57 and $50, respectively. Tax Brazil (AWAB)— In March 2013, AWAB was notified by the Brazilian Federal Revenue Office (RFB) that approximately $110 (R$220) of value added tax credits previously claimed were being disallowed and a penalty of 50% was assessed. Of this amount, AWAB received $41 (R$82) in cash in May 2012. The value added tax credits were claimed by AWAB for both fixed assets and export sales related to the Juruti bauxite mine and Alumar refinery expansion for tax years 2009 through 2011. The RFB has disallowed credits they allege belong to the consortium in which AWAB owns an interest and should not have been claimed by AWAB. Credits have also been disallowed as a result of challenges to apportionment methods used, questions about the use of the credits, and an alleged lack of documented proof. AWAB presented defense of its claim to the RFB on April 8, 2013. In February 2022, the RFB notified AWAB that it had inspected the value added tax credits claimed for 2012 and disallowed $4 (R$19). In its decision, the RFB allowed credits of $14 (R$65) that were similar to those previously disallowed for 2009 through 2011. In July 2022, the RFB notified AWAB that it had inspected the value added tax credits claimed for 2013 and disallowed $13 (R$70). In its decision, the RFB allowed credits of $16 (R$84) that were similar to those previously disallowed for 2009 through 2011. The decisions on the 2012 and 2013 credits provide positive evidence to support management’s opinion that there is no basis for these credits to be disallowed. AWAB received the 2012 allowed credits with interest of $9 (R$44) in March 2022 and the 2013 allowed credits with interest of $6 (R$31) in August 2022. AWAB will continue to dispute the credits that were disallowed for 2012 and 2013. If AWAB is successful in this administrative process, the RFB would have no further recourse. If unsuccessful in this process, AWAB has the option to litigate at a judicial level. Separately from AWAB’s administrative appeal, in June 2015, a new tax law was enacted repealing the provisions in the tax code that were the basis for the RFB assessing a 50% penalty in this matter. As such, the estimated range of reasonably possible loss for these matters is $0 to $49 (R$239). It is management’s opinion that the allegations have no basis; however, at this time, the Company is unable to reasonably predict an outcome for this matter. Australia (AofA)— In December 2019, AofA received a statement of audit position (SOAP) from the Australian Taxation Office (ATO) related to the pricing of certain historic third-party alumina sales. The SOAP proposed adjustments that would result in additional income tax payable by AofA. During 2020, the SOAP was the subject of an independent review process within the ATO. At the conclusion of this process, the ATO determined to continue with the proposed adjustments and issued Notices of Assessment (the Notices) that were received by AofA on July 7, 2020. The Notices asserted claims for income tax payable by AofA of approximately $145 (A$214). The Notices also included claims for compounded interest on the tax amount totaling approximately $481 (A$707). On September 17, 2020, the ATO issued a position paper with its preliminary view on the imposition of administrative penalties related to the tax assessment issued to AofA. This paper proposed penalties of approximately $87 (A$128). AofA disagreed with the Notices and with the ATO’s proposed position on penalties. During 2020, AofA lodged formal objections to the Notices, provided a submission on the ATO’s imposition of interest and submitted a response to the ATO’s position paper on penalties. After the ATO completes its review of AofA’s response to the penalties position paper, the ATO could issue a penalty assessment. To date, AofA has not received a response to its submission on the ATO’s imposition of interest or its response to the ATO’s position paper on penalties. Through February 1, 2022, AofA did not receive a response from the ATO on AofA’s formal objections to the Notices and, on that date, AofA submitted statutory notices to the ATO requiring the ATO to make decisions on AofA’s objections within a 60-day period. On April 1, 2022, the ATO issued its decision disallowing the Company’s objections related to the income tax assessment, while the position on penalties and interest remains outstanding. On April 29, 2022, AofA filed proceedings in the Australian Administrative Appeals Tribunal (AAT) against the ATO to contest the Notices, a process which could last several years. The AAT held the first directions hearing on July 25, 2022 ordering AofA to file its evidence and related materials by November 4, 2022, ATO to file its materials by April 14, 2023 and AofA to file reply materials by May 26, 2023. AofA filed its evidence and related materials on November 4, 2022. The ATO did not file its materials by April 14, 2023. At a directions hearing on May 17, 2023, the ATO was granted an extension to file its materials by August 18, 2023. At a directions hearing on September 26, 2023, the ATO was granted an additional extension to file its materials by November 3, 2023. The ATO filed its materials on November 13, 2023. At a directions hearing on November 22, 2023, AofA was ordered to file any reply materials by March 15, 2024. The substantive hearing is scheduled for June 2024. The Company maintains that the sales subject to the ATO’s review, which were ultimately sold to Aluminium Bahrain B.S.C., were the result of arm’s length transactions by AofA over two decades and were made at arm’s length prices consistent with the prices paid by other third-party alumina customers. In accordance with the ATO’s dispute resolution practices, AofA paid 50% of the assessed income tax amount exclusive of interest and any penalties, or approximately $74 (A$107), during the third quarter 2020, and the ATO is not expected to seek further payment prior to final resolution of the matter. If AofA is ultimately successful, any amounts paid to the ATO as part of the 50% payment would be refunded. AofA funded the payment with cash on hand and recorded the payment within Other noncurrent assets as a noncurrent prepaid tax asset; the related December 31, 2023 balance is $73 (A$107). Further interest on the unpaid tax will continue to accrue during the dispute. The initial interest assessment and the additional interest accrued are deductible against taxable income by AofA but would be taxable as income in the year the dispute is resolved if AofA is ultimately successful. AofA applied this deduction beginning in the third quarter of 2020, reducing cash tax payments. At December 31, 2023 and December 31, 2022, total reductions in cash tax payments were $199 (A$293) and $174 (A$260), respectively, and are reflected within Other noncurrent liabilities and deferred credits as a noncurrent accrued tax liability. The Company continues to believe it is more likely than not that AofA’s tax position will be sustained and therefore is not recognizing any tax expense in relation to this matter. However, because the ultimate resolution of this matter is uncertain at this time, the Company cannot predict the potential loss or range of loss associated with the outcome, which may materially affect its results of operations and financial condition. References to any assessed U.S. dollar amounts presented in connection with this matter have been converted into U.S. dollars from Australian dollars based on the exchange rate in the respective period. AofA is part of the Company’s joint venture with Alumina Limited, an Australian public company listed on the Australian Securities Exchange. The Company and Alumina Limited own 60% and 40%, respectively, of the joint venture entities, including AofA. Other Spain— In July 2019, the Company completed the divestiture of the Avilés and La Coruña (Spain) aluminum facilities to PARTER Capital Group AG (PARTER) in a sale process endorsed by the Spanish government and supported by the workers’ representatives following a collective dismissal process. In connection with the divestiture, Alcoa committed to make financial contributions to the divested entities of up to $95; a total of $78 was paid through December 31, 2021. In early 2020, PARTER sold a majority stake in the facilities to an unrelated party. Alcoa had no knowledge of the subsequent transaction prior to its announcement and on August 28, 2020, Alcoa filed a lawsuit with the Court of First Instance in Madrid, Spain asserting that the sale was in breach of the sale agreement between Alcoa and PARTER. In June 2023, the Court of First Instance in Madrid issued a declaratory judgment in Alcoa’s favor ruling that the transaction between PARTER and the unrelated party was a breach of the sale agreement. There was no financial compensation to the Company as a result of this ruling. Related to this subsequent sale transaction, certain proceedings and investigations were initiated by or at the request of the employees of the facilities against their current employers, the new owners of the current employers, and Alcoa, alleging that certain agreements from the 2019 collective dismissal process remain in force and that, under such agreements, Alcoa remains liable for certain related employment benefits. During 2022, Alcoa reached a Global Settlement Agreement (GSA) with the workers of the divested Avilés and La Coruña facilities to settle various legal disputes related to the 2019 divestiture, and Alcoa recorded a charge of $79 in Restructuring and other charges, net to reflect its estimated liability for the GSA. In July 2023, the Supreme Court of Spain ratified the GSA. Upon completion of the remaining administrative and judicial approvals, the Company made cash payments of $76 to the former employees of the facilities in 2023 in accordance with the GSA. The remaining payments will be made in the early 2024. General In addition to the matters discussed above, various other lawsuits, claims, and proceedings have been or may be instituted or asserted against Alcoa Corporation, including those pertaining to environmental, safety and health, commercial, tax, product liability, intellectual property infringement, employment, and employee and retiree benefit matters, and other actions and claims arising out of the normal course of business. While the amounts claimed in these other matters may be substantial, the ultimate liability is not readily determinable because of the considerable uncertainties that exist. Accordingly, it is possible that the Company’s liquidity or results of operations in a particular period could be materially affected by one or more of these other matters. However, based on facts currently available, management believes that the disposition of these other matters that are pending or asserted will not have a material adverse effect, individually or in the aggregate, on the financial position of the Company. Commitments Purchase Obligations. Alcoa Corporation is party to unconditional purchase obligations for energy that expire between 2040 and 2041. Commitments related to these contracts total $56 in 2024, $59 in 2025, $61 in 2026, $63 in 2027, $65 in 2028, and $770 thereafter. Expenditures under these contracts totaled $53 in 2023, $58 in 2022, and $86 in 2021. Additionally, the Company has entered into other purchase commitments for energy, raw materials, and other goods and services, which total $3,896 in 2024, $1,998 in 2025, $1,566 in 2026, $1,448 in 2027, $1,407 in 2028, and $8,757 thereafter. AofA has a gas supply agreement to power its three alumina refineries in Western Australia which began in July 2020 for a 12-year period. The terms of this agreement required AofA to make a prepayment of $500 prior to 2017. At December 31, 2023, prepayments of $37 and $283 were included in Prepaid expenses and other current assets and Other noncurrent assets (see Note U), respectively, on the accompanying Consolidated Balance Sheet. At December 31, 2022, prepayments of $37 and $311 were included in Prepaid expenses and other current assets and Other noncurrent assets (see Note U), respectively, on the accompanying Consolidated Balance Sheet. Guarantees of Third Parties. As of December 31, 2023 and 2022, the Company had no outstanding potential future payments for guarantees issued on behalf of a third party. Bank Guarantees and Letters of Credit. Alcoa Corporation and its subsidiaries have outstanding bank guarantees and letters of credit related to, among others, energy contracts, environmental obligations, legal and tax matters, leasing obligations, workers compensation, and customs duties. The total amount committed under these instruments, which automatically renew or expire at various dates between 2024 and 2025, was $294 (includes $86 issued under a standby letter of credit agreement —see below) at December 31, 2023. Additionally, ParentCo has outstanding bank guarantees and letters of credit related to the Company of $13 at December 31, 2023. In the event ParentCo would be required to perform under any of these instruments, ParentCo would be indemnified by Alcoa Corporation in accordance with the Separation and Distribution Agreement. Likewise, the Company has outstanding bank guarantees and letters of credit related to ParentCo of $8 at December 31, 2023. In the event Alcoa Corporation would be required to perform under any of these instruments, the Company would be indemnified by ParentCo in accordance with the Separation and Distribution Agreement. In December 2023, AofA committed to provide a bank guarantee for approximately $68 (A$100) which demonstrates Alcoa’s confidence that its operations will not impair drinking water supplies. In August 2017, Alcoa Corporation entered into a standby letter of credit agreement, which expires on June 27, 2024 (amended in August 2018, May 2019, May 2021, June 2022, and January 2024), with three financial institutions. The agreement provides for a $200 facility used by the Company for matters in the ordinary course of business. Alcoa Corporation’s obligations under this facility are secured in the same manner as obligations under the Company’s revolving credit facility. Additionally, this facility contains similar representations and warranties and affirmative, negative, and financial covenants as the Company’s Revolving Credit Facility (see Note M). As of December 31, 2023, letters of credit aggregating $86 were issued under this facility. Surety Bonds. Alcoa Corporation has outstanding surety bonds primarily related to tax matters, contract performance, workers compensation, environmental-related matters, and customs duties. The total amount committed under these bonds, which automatically renew or expire at various dates between 2024 and 2028, was $190 at December 31, 2023. Additionally, ParentCo has outstanding surety bonds related to the Company of $8 at December 31, 2023. In the event ParentCo would be required to perform under any of these instruments, ParentCo would be indemnified by Alcoa Corporation in accordance with the Separation and Distribution Agreement. Likewise, the Company has outstanding surety bonds related to ParentCo of $5 at December 31, 2023. In the event Alcoa Corporation would be required to perform under any of these instruments, the Company would be indemnified by ParentCo in accordance with the Separation and Distribution Agreement. |
Leasing |
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| Leasing | T. Leasing The Company records a right-of-use asset and lease liability for several types of operating leases, including land and buildings, alumina refinery process control technology, plant equipment, vehicles, and computer equipment. These amounts are equivalent to the aggregate future lease payments on a discounted basis. The leases have remaining terms of less than to 59 years. The discount rate applied in determining the present value of lease payments is the Company’s incremental borrowing rate at the lease commencement date, unless there is a rate implicit in the lease agreement. The Company does not have material financing leases. Lease expense and operating cash flows include:
The weighted average lease term and weighted average discount rate were as follows:
The following represents the aggregate right-of-use assets and related lease obligations recognized in the Consolidated Balance Sheet:
New leases of $76 and $26 were added during the years ended December 31, 2023 and 2022, respectively. The future cash flows related to the operating lease obligations as of December 31, 2023 were as follows:
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Other Financial Information |
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| Other Financial Information [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other Financial Information | U. Other Financial Information Interest Cost Components
Other Expenses (Income), Net
In 2023, Other, net of $62 was primarily related to interest income on interest bearing accounts. In 2022, Other, net of $50 was primarily related to interest income for the Brazil value added tax credits (see Note S). In 2021, Net loss (gain) from asset sales of $354 was primarily related to the sales of the Rockdale site, the Eastalco site, and the Warrick Rolling Mill (see Note C). Other Noncurrent Assets
Prepaid gas transmission contract—As part of a previous sale transaction of an equity investment, Alcoa maintained access to approximately 30% of the Dampier to Bunbury Natural Gas Pipeline transmission capacity in Western Australia for gas supply to three alumina refineries. At December 31, 2023 and 2022, AofA had an asset of $297 and $285, respectively, representing prepayments made under the agreement for future gas transmission services. Value added tax credits—The Value added tax (VAT) credits (federal and state) relate to two of the Company’s subsidiaries in Brazil, AWAB and Alumínio, concerning the Alumar smelter and refinery and the Juruti mine. The mine, refinery and smelter pay VAT on the purchase of goods and services used in the mining, alumina, and production process. The credits generally can be utilized to offset the VAT charged on domestic sales of bauxite, alumina, and aluminum. In March 2021, the Brazil Federal Supreme Court provided clarification on an earlier ruling that found the inclusion of state VAT within the federal VAT tax base to be unconstitutional. After receiving further clarification from the court in August 2021, the Company finalized the amount of its recovery claim and submitted the claim to the tax authorities in the fourth quarter and received acknowledgment of the claim in January 2022. As a result, in the fourth quarter of 2021, the Company recorded $95 of additional VAT credits in Other noncurrent assets, $47 payable to Arconic Corporation within Other noncurrent liabilities, $34 in Sales, and $14 of interest income within Other (income) expenses, net. The amount due to Arconic Corporation represents VAT payments related to an Arconic subsidiary previously owned by Alumínio for a portion of the claim years and covered under agreements related to the Separation Transaction (see Note A). In the fourth quarter of 2018, after an assessment of the future realizability of Brazil state VAT credits recorded, the Company established an allowance on the accumulated state VAT credit balances and stopped recording any future credit benefits. With the restart of the Alumar smelter and its first metal sales in June 2022, the Company had the ability to monetize these credits. In June 2022, the Company reversed the allowance with a credit of $83 to Restructuring and other charges, net and reversed the subsequent additions to the valuation allowance with a credit to Cost of goods sold of $46 (same accounts as when incurred). Other Noncurrent Liabilities and Deferred Credits
Deferred energy credits—Deferred energy credits relate to cash received for 2022 and 2021 carbon dioxide emissions related to the San Ciprián smelter and refinery during the years ended December 31, 2023 and 2022, respectively, from a governmental agency in Spain. The terms of the credits require the Company to comply with certain conditions for a period of three years. These deferred credits will be recognized as a reduction to Cost of goods sold once it is determined to be probable the Company will satisfy all conditions. Should the Company not meet all conditions during the three-year period, the credits will be repaid to the governmental agency. Value added tax credits payable to Arconic Corporation—See, Other noncurrent assets—Value added tax credits, above.
Cash and Cash Equivalents and Restricted Cash
Restricted cash primarily relates to commitments made for the December 2021 and February 2023 viability agreements for the San Ciprián restart (see Note D). At December 31, 2023, the Company had restricted cash of $91 remaining to be made available for $118 in capital improvements at the site and $35 in smelter restart costs. The Company incurred $28 of capital investment expenditures against the commitments during 2023. Cash Flow Information Cash paid for interest and income taxes was as follows:
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Supplier Finance Programs |
12 Months Ended |
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Dec. 31, 2023 | |
| Supplier Finance Programs [Abstract] | |
| Supplier Finance Programs | V. Supplier Finance Programs The Company has various supplier finance programs with third-party financial institutions that are made available to suppliers to facilitate payment term negotiations. Under the terms of these agreements, participating suppliers receive payment in advance of the payment date from third-party financial institutions for qualifying invoices. Alcoa’s obligations to its suppliers, including amounts due and payment terms, are not impacted by its suppliers’ participation in these programs. The Company does not pledge any assets as security or provide any guarantees beyond payment of outstanding invoices at maturity under these arrangements. The Company does not pay fees to the financial institutions under these arrangements. At December 31, 2023 and December 31, 2022, qualifying supplier invoices outstanding under these programs were $104 and $185, respectively, and have payment terms ranging from 50 to 110 days. These obligations are included in Accounts payable, trade on the accompanying Consolidated Balance Sheet. |
Subsequent Events |
12 Months Ended |
|---|---|
Dec. 31, 2023 | |
| Subsequent Events [Abstract] | |
| Subsequent Events | W. Subsequent Events On January 8, 2024, Alcoa announced the full curtailment of the Kwinana refinery beginning in the second quarter of 2024. The refinery has an annual nameplate capacity of 2.2 million metric tons and has been operating at approximately 80 percent of its nameplate capacity since January 2023, when the Company reduced production in response to a domestic natural gas shortage in Western Australia due to production challenges experienced by key gas suppliers. The Company’s decision to fully curtail the refinery was made based on a variety of factors, including the refinery’s age, scale, operating costs and current bauxite grades, in addition to current market conditions. The refinery currently has approximately 800 employees and this number will be reduced to approximately 250 in the third quarter of 2024, when alumina production will cease. Certain processes will continue until about the third quarter of 2025, when the employee number will be further reduced to approximately 50. In the first quarter of 2024, Alcoa will record restructuring charges between $180 and $200 related to the curtailment of the refinery. The charges include approximately $81 for water management costs, $55 for employee related costs, $26 for asset retirement obligations, and $18 of other costs. Alcoa’s share of related cash outlays of approximately $115 (which includes existing employee related liabilities and asset retirement obligations) is expected to be spent in 2024 ($80) and 2025 ($35). |
Basis of Presentation (Policies) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||
| Accounting Policies [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||
| Basis of Presentation | Basis of Presentation. The Consolidated Financial Statements of Alcoa Corporation are prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). In accordance with GAAP, certain situations require management to make estimates based on judgments and assumptions, which may affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements. They also may affect the reported amounts of revenues and expenses during the reporting periods. Management uses historical experience and all available information to make these estimates. Management regularly evaluates the judgments and assumptions used in its estimates, and results could differ from those estimates upon future events and their effects or new information. |
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| Principles of Consolidation | Principles of Consolidation. The Consolidated Financial Statements of the Company include the accounts of Alcoa Corporation and companies in which Alcoa Corporation has a controlling interest, including those that comprise the Alcoa World Alumina & Chemicals (AWAC) joint venture (see below). Intercompany transactions have been eliminated. The equity method of accounting is used for investments in affiliates and other joint ventures over which the Company has significant influence but does not have effective control. Investments in affiliates in which Alcoa Corporation cannot exercise significant influence are accounted at cost less any impairment, a measurement alternative in accordance with GAAP. AWAC is an unincorporated global joint venture between Alcoa Corporation and Alumina Limited and consists of several affiliated operating entities, which own, have an interest in, or operate the bauxite mines and alumina refineries within the Company’s Alumina segment (except for the Poços de Caldas mine and refinery, portions of the São Luís refinery, and investment in Mineração Rio do Norte S.A. (MRN) until its sale in April 2022, all in Brazil) and a portion (55%) of the Portland smelter (Australia) within the Company’s Aluminum segment. Alcoa Corporation owns 60% and Alumina Limited owns 40% of these individual entities, which are consolidated by the Company for financial reporting purposes and include Alcoa of Australia Limited (AofA), Alcoa World Alumina LLC (AWA), Alcoa World Alumina Brasil Ltda. (AWAB), and Alúmina Española, S.A. (Española). Alumina Limited’s interest in the equity of such entities is reflected as Noncontrolling interest on the accompanying Consolidated Balance Sheet. Management evaluates whether an Alcoa Corporation entity or interest is a variable interest entity and whether the Company is the primary beneficiary. Consolidation is required if both of these criteria are met. Alcoa Corporation does not have any variable interest entities requiring consolidation. |
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| Related Party Transactions | Related Party Transactions. Alcoa Corporation buys products from and sells products to various related companies, consisting of entities in which the Company retains a 50% or less equity interest, at negotiated prices between the two parties. These transactions were not material to the financial position or results of operations of Alcoa Corporation for all periods presented. |
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| Cash Equivalents | Cash Equivalents. Cash equivalents are highly liquid investments purchased with an original maturity of three months or less. |
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| Restricted Cash | Restricted Cash. Restricted cash is included with Cash and cash equivalents when reconciling the Cash and cash equivalents and restricted cash at beginning of year and Cash and cash equivalents and restricted cash at end of year on the accompanying Statement of Consolidated Cash Flows. Current restricted cash amounts are reported in Prepaid expenses and other current assets on the accompanying Consolidated Balance Sheet. Noncurrent restricted cash amounts are reported in Other noncurrent assets on the accompanying Consolidated Balance Sheet (see Note U for a reconciliation of Cash and cash equivalents and restricted cash). |
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| Inventory Valuation | Inventory Valuation. Inventories are carried at the lower of cost or net realizable value, with the cost of inventories principally determined under the average cost method. |
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| Properties, Plants, and Equipment | Properties, Plants, and Equipment. Properties, plants, and equipment are recorded at cost. Interest related to the construction of qualifying assets is capitalized as part of the construction costs. Depreciation is recorded principally on the straight-line method over the estimated useful lives of the assets. Depreciation is recorded on temporarily idled facilities until such time management approves a permanent closure. The following table details the weighted average useful lives of structures and machinery and equipment by type of operation (numbers in years):
Repairs and maintenance are charged to expense as incurred while costs for significant improvements that add productive capacity or that extend the useful life are capitalized. Gains or losses from the sale of assets are generally recorded in Other expenses (income), net. Properties, plants, and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets (asset group) may not be recoverable. Recoverability of assets is determined by comparing the estimated undiscounted net cash flows of the operations related to the assets (asset group) to their carrying amount. An impairment loss would be recognized when the carrying amount of the assets (asset group) exceeds the fair value. The amount of the impairment loss to be recorded is calculated as the excess of the carrying value of the assets (asset group) over their fair value, with fair value determined using the best information available, which generally is a discounted cash flow (DCF) model. The determination of what constitutes an asset group, the associated estimated undiscounted net cash flows, and the estimated useful lives of assets also require significant judgments. |
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| Leases | Leases. The Company determines whether an arrangement is a lease at the inception of the arrangement based on the terms and conditions in the contract. A contract contains a lease if there is an identified asset which the Company has the right to control. Lease right-of-use (ROU) assets are included in Properties, plants, and equipment, net with the corresponding operating lease liabilities included within Other current liabilities and Other noncurrent liabilities and deferred credits on the accompanying Consolidated Balance Sheet. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company uses its incremental borrowing rate at the commencement date in determining the present value of lease payments unless a rate is implicit in the lease. Lease terms include options to extend the lease when it is reasonably certain that those options will be exercised. Leases with an initial term of 12 months or less, including anticipated renewals, are not recorded on the Consolidated Balance Sheet. The Company made a policy election not to record any non-lease components of a lease agreement in the lease liability. Variable lease payments are not presented as part of the ROU asset or liability recorded at the inception of a contract. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. |
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| Equity Investments | Equity Investments. Alcoa invests in a number of privately-held companies, primarily through joint ventures and consortia, which are accounted for using the equity method. The equity method is applied in situations where the Company has the ability to exercise significant influence, but not control, over the investee. Management reviews equity investments for impairment whenever certain indicators are present suggesting that the carrying value of an investment is not recoverable. |
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| Deferred Mining Costs | Deferred Mining Costs. Alcoa incurs deferred mining costs during the development stage of a mine life cycle. Such costs include the construction of access and haul roads, detailed drilling and geological analysis to further define the grade and quality of the known bauxite, and overburden removal costs. These costs relate to sections of the related mines where the Company is currently extracting bauxite or preparing for production in the near term. These sections are outlined and planned incrementally and generally are mined over periods ranging from to five years, depending on specific mine plans. The amount of geological drilling and testing necessary to determine the economic viability of the bauxite deposit being mined is such that the reserves are considered to be proven. Deferred mining costs are amortized on a units-of-production basis and included in Other noncurrent assets on the accompanying Consolidated Balance Sheet. |
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| Goodwill and Other Intangible Assets | Goodwill and Other Intangible Assets. Goodwill is not amortized but is reviewed for impairment annually (in the fourth quarter) or more frequently if indicators of impairment exist or if a decision is made to sell or exit a business.
Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. Beginning in January 2023, the Company changed its operating segments, by combining the Bauxite and Alumina segments, and reported its financial results in the following two segments: (i) Alumina and (ii) Aluminum (see Note E). The Company has three reporting units, of which two are included in the Aluminum segment (smelting/casting and energy generation). The remaining reporting unit is the Alumina segment. Of these three reporting units, only contains goodwill (see Note L). Goodwill is tested for impairment by assessing qualitative factors to determine whether it is more likely than not (greater than 50%) that the fair value of the reporting unit is less than its carrying amount or performing a quantitative assessment using a discounted cash flow model. If the qualitative assessment indicates a possible impairment, then a quantitative impairment test is performed to determine the fair value of the reporting unit using a discounted cash flow method. Otherwise, no further analysis is required. Under the quantitative assessment, the evaluation of impairment involves comparing the current fair value of each reporting unit to its carrying value, including goodwill. In the event the estimated fair value of a reporting unit is less than the carrying value, an impairment loss equal to the excess of the reporting unit’s carrying value over its fair value not to exceed the total amount of goodwill applicable to that reporting unit would be recognized. Alcoa’s policy for its annual review of goodwill is to perform the quantitative impairment test for its reporting unit containing goodwill at least once during every three-year period. Intangible assets with finite useful lives are amortized generally on a straight-line basis over the periods benefited. The following table details the weighted average useful lives of software and other intangible assets by type of operation (numbers in years):
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| Asset Retirement Obligations | Asset Retirement Obligations. Alcoa recognizes asset retirement obligations (AROs) related to legal obligations associated with the standard operation of bauxite mines, alumina refineries, and aluminum smelters. These AROs consist primarily of costs associated with mine reclamation, closure of bauxite residue areas, spent pot lining and regulated waste materials disposal, and landfill closure. Additionally, costs are recorded as AROs upon management’s decision to permanently close and demolish certain structures and for any significant lease restoration obligations. The fair values of these AROs are recorded on a discounted basis at the time the obligation is incurred and accreted over time for the change in present value; related accretion is recorded as a component of Cost of goods sold. Additionally, the Company capitalizes asset retirement costs by increasing the carrying amount of the related long-lived assets and depreciating these assets over their remaining useful life. The fair values for AROs are determined using significant assumptions, including engineering designs for construction or closure, materials and services costs, regulatory requirements, volume of regulated material to be removed, disposition of demolition materials, and timing to complete construction or closure. Subsequent adjustments to estimates of previously established AROs for current operations are capitalized by increasing the carrying amount of the related long-lived assets and depreciating these assets over their remaining useful life. Adjustments to estimates of AROs for closed locations are charged to Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note R). Certain conditional asset retirement obligations related to alumina refineries, aluminum smelters, and energy generation facilities have not been recorded in the Consolidated Financial Statements due to uncertainties surrounding the ultimate settlement date. The fair value of these asset retirement obligations will be recorded when a reasonable estimate of the ultimate settlement date can be made. |
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| Environmental Matters | Environmental Matters. Environmental related expenditures for current operations are expensed as a component of Cost of goods sold or capitalized, as appropriate. Expenditures relating to existing conditions caused by past operations, generally for closed locations which will not contribute to future revenues, are charged to Restructuring and other charges, net. Liabilities are recorded when remediation costs are probable and can be reasonably estimated. In instances where the Company has ongoing monitoring and maintenance responsibilities, it is Alcoa’s policy to maintain a reserve equal to five years of expected costs. The liability is continuously reviewed and adjusted to reflect current remediation progress, rate and pricing changes, actual volumes of material requiring management, changes to the original assumptions regarding how the site was to be remediated, and other factors that may be relevant, including changes in technology or regulations. The estimates may also include costs related to other potentially responsible parties to the extent that Alcoa has reason to believe such parties will not fully pay their proportionate share. |
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| Litigation Matters | Litigation Matters. For asserted claims and assessments, liabilities are recorded when an unfavorable outcome of a matter is deemed to be probable and the loss is reasonably estimable. With respect to unasserted claims or assessments, liabilities are recorded when the probability that an assertion will be made is likely, an unfavorable outcome of the matter is deemed to be probable, and the loss is reasonably estimable. Legal matters are reviewed on a continuous basis to determine if there has been a change in management’s judgment regarding the likelihood of an unfavorable outcome or the estimate of a potential loss. Legal costs, which are primarily for general litigation, environmental compliance, tax disputes, and general corporate matters, are expensed as incurred. |
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| Revenue Recognition | Revenue Recognition. The Company recognizes revenue when it satisfies a performance obligation(s) in accordance with the provisions of a customer order or contract. This is achieved when control of the product has been transferred to the customer, which is generally determined when title, ownership, and risk of loss pass to the customer, all of which occurs upon shipment or delivery of the product. The shipping terms vary across all businesses and depend on the product, the country of origin, and the type of transportation. Accordingly, the sale of Alcoa’s products to its customers represent single performance obligations for which revenue is recognized at a point in time, except for the Company’s Energy product division in which the customer simultaneously receives and consumes electricity (see Note E). Revenue is based on the consideration the Company expects to receive in exchange for its products. Returns and other adjustments have not been material. Based on the foregoing, no significant judgment is required to determine when control of a product has been transferred to a customer. The Company considers shipping and handling activities as costs to fulfill the promise to transfer the related products. As a result, customer payments of shipping and handling costs are recorded as a component of revenue. Taxes collected (e.g., sales, use, value added, excise) from its customers related to the sale of its products are remitted to governmental authorities and excluded from Sales. |
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| Cost of Goods Sold | Cost of goods sold. The Company includes the following in Cost of goods sold: operating costs of our two segments, excluding depreciation, depletion, and amortization, but including all production related costs: raw materials consumed; purchases of metal for consumption; conversion costs, such as labor, materials, and utilities; equity earnings of certain investments integral to the Company’s supply chain; and plant administrative expenses. Also included in Cost of goods sold are: costs related to the Transformation function, which focuses on the management of expenses and obligations of previously closed operations; pension and other postretirement benefit service cost for employees maintaining closed locations; purchases of bauxite from offtake or other supply agreements, alumina to satisfy customer commitments, and metal for trade; and other costs not included in the operating costs of the segments. |
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| Selling, General Administrative, and Other Expenses | Selling, general administrative, and other expenses. The Company includes the costs of corporate-wide functional support in Selling, general administrative, and other expenses. Such costs include: executive; sales; marketing; strategy; operations administration; finance; information technology; legal; human resources; and government affairs and communications. |
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| Stock-Based Compensation | Stock-Based Compensation. Compensation expense for employee equity grants is recognized using the non-substantive vesting period approach, in which the expense is recognized ratably over the requisite service period based on the grant date fair value. Forfeitures are accounted for as they occur. The fair value of performance stock units containing a market condition is valued using a Monte Carlo valuation model. Determining the fair value at the grant date requires judgment, including estimates for the average risk-free interest rate, and volatility. These assumptions may differ significantly between grant dates because of changes in the actual results of these inputs that occur over time. As of January 1, 2021, the Company no longer grants stock options. Refer to Note N for more information regarding stock-based compensation. |
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| Pensions and Other Postretirement Benefits | Pension and Other Postretirement Benefits. Alcoa sponsors several defined benefit pension plans and health care postretirement benefit plans. The Company recognizes on a plan-by-plan basis the net funded status of these pension and postretirement benefit plans as either an asset or a liability on its Consolidated Balance Sheet. The net funded status represents the difference between the fair value of each plan’s assets and the benefit obligation of the respective plan. The benefit obligation represents the present value of the estimated future benefits the Company currently expects to pay to plan participants based on past service. Unrecognized gains and losses related to the plans are deferred in Accumulated other comprehensive loss on the Consolidated Balance Sheet until amortized into earnings. The plan assets and benefit obligations are measured at the end of each year or more frequently, upon the occurrence of certain events such as a significant plan amendment, settlement, or curtailment. For interim plan remeasurements, it is the Company’s policy to record the related accounting impacts within the same quarter as the triggering event. Liabilities and expenses for pension and other postretirement benefits are determined using actuarial methodologies and incorporate significant assumptions, including the interest rate used to discount the future estimated liability, the expected long-term rate of return on plan assets, and several assumptions relating to the employee workforce (salary increases, health care cost trend rates, retirement age, and mortality). The yield curve model used to develop the discount rate parallels the plans’ projected cash flows and has a weighted average duration of 10 years. The underlying cash flows of the high-quality corporate bonds included in the model exceed the cash flows needed to satisfy the Company’s plan obligations multiple times. If a deep market of high-quality corporate bonds does not exist in a country, then the yield on government bonds plus a corporate bond yield spread is used. The expected long-term rate of return on plan assets is generally applied to a five-year market-related value of plan assets (a four-year average or the fair value at the plan measurement date is used for certain non-U.S. plans). The process used by management to develop this assumption is one that relies on forward-looking investment returns by asset class. Management incorporates expected future investment returns on current and planned asset allocations using information from various external investment managers and consultants, as well as management’s own judgment. Mortality rate assumptions are based on mortality tables and future improvement scales published by third parties, such as the Society of Actuaries, and consider other available information including historical data as well as studies and publications from reputable sources. A change in one or a combination of these assumptions, or the effects of actual results differing from assumptions, could have a material impact on Alcoa’s projected benefit obligation. These changes or differences are recorded in Accumulated other comprehensive loss and are amortized into earnings as a component of the net periodic benefit cost (income) over the average future working lifetime or average remaining life expectancy, as appropriate, of the plan’s participants. One-time accounting impacts, such as curtailment and settlement losses (gains), are recognized immediately and are reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net on the accompanying Statement of Consolidated Operations. Refer to Note O for more information regarding pension and other postretirement benefits including accounting impacts of current year actions. |
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| Derivatives and Hedging | Derivatives and Hedging. Derivatives are held for purposes other than trading and are part of a formally documented risk management program. Alcoa accounts for hedges of firm customer commitments for aluminum as fair value hedges. The fair values of the derivatives and changes in the fair values of the underlying hedged items are reported as assets and liabilities in the Consolidated Balance Sheet. Changes in the fair values of these derivatives and underlying hedged items generally offset and are recorded each period in Sales, consistent with the underlying hedged item. The Company accounts for certain hedges of foreign currency exposures and certain forecasted transactions as cash flow hedges. The fair values of the derivatives are recorded as assets and liabilities in the Consolidated Balance Sheet. The changes in the fair values of these derivatives are recorded in Other comprehensive (loss) income and are reclassified to Sales, Cost of goods sold, or Other expenses (income), net in the period in which earnings are impacted by the hedged items or in the period that the transaction no longer qualifies as a cash flow hedge. These contracts cover the same periods as known or expected exposures, generally not exceeding five years. If no hedging relationship is designated, the derivative is marked to market through Other expenses (income), net. Cash flows from derivatives are recognized in the Statement of Consolidated Cash Flows in a manner consistent with the underlying transactions. |
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| Income Taxes | Income Taxes. The provision for income taxes is determined using the asset and liability approach of accounting for income taxes. Under this approach, the provision for income taxes represents income taxes paid or payable (or received or receivable) for the current year plus the change in deferred taxes during the year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid, resulting from differences between the financial and tax bases of Alcoa’s assets and liabilities and are adjusted for changes in tax rates and tax laws when enacted. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not (greater than 50%) that a tax benefit will not be realized. In evaluating the need for a valuation allowance, management applies judgment in assessing all available positive and negative evidence and considers all potential sources of taxable income. Deferred tax assets for which no valuation allowance is recorded may not be realized upon changes in facts and circumstances, resulting in a future charge to establish a valuation allowance. Existing valuation allowances are re-examined under the same standards of positive and negative evidence. If it is determined that it is more likely than not that a deferred tax asset will be realized, the appropriate amount of the valuation allowance, if any, is released. Deferred tax assets and liabilities are also re-measured to reflect changes in underlying tax rates due to law changes and the granting and lapse of tax holidays. Tax benefits related to uncertain tax positions taken or expected to be taken on a tax return are recorded when such benefits meet a more likely than not threshold. Otherwise, these tax benefits are recorded when a tax position has been effectively settled, which means that the statute of limitations has expired or the appropriate taxing authority has completed their examination even though the statute of limitations remains open. Interest and penalties related to uncertain tax positions are recognized as part of the provision for income taxes and are accrued in the period that such interest and penalties would be applicable under relevant tax law until such time that the related tax benefits are recognized. |
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| Foreign Currency | Foreign Currency. The local currency is the functional currency for Alcoa’s significant operations outside the United States, except for certain operations in Canada and Iceland, and a holding and trading company in the Netherlands, where the U.S. dollar is used as the functional currency. The determination of the functional currency for Alcoa’s operations is made based on the appropriate economic and management indicators. Where local currency is the functional currency, assets and liabilities are translated into U.S. dollars using period end exchange rates and income and expenses are translated using the average exchange rates for the reporting period. Unrealized foreign currency translation gains and losses are deferred in Accumulated other comprehensive loss on the Consolidated Balance Sheet. Recently Adopted Accounting Guidance. On January 1, 2023, the Company adopted Accounting Standard Update (ASU) No. 2022-04 which requires a buyer in a supplier finance program to disclose qualitative and quantitative information about its supplier finance programs, including the key terms of the program, the amount of obligations outstanding at the end of the reporting period, a description of where those obligations are presented in the balance sheet, and effective January 1, 2024, a roll-forward of such amounts during the annual period. The adoption of this guidance resulted in enhanced disclosures regarding these programs (see Note V) and did not have a material impact on the Company's Consolidated Financial Statements. Recently Issued Accounting Guidance. In December 2023, the Financial Accounting Standards Board (FASB) issued ASU No. 2023-09 which includes changes to income tax disclosures, including greater disaggregation of information in the rate reconciliation and disclosure of taxes paid by jurisdiction. The guidance is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. The adoption of this guidance will provide enhanced disclosures regarding income taxes and will not have a material impact on the Company’s financial statements. In November 2023, the FASB issued ASU No. 2023-07 which requires disclosure of significant segment expenses regularly provided to the chief operating decision maker (CODM), other segment items (not included in significant segment expenses for each reportable segment), the title and position of the CODM, and an explanation of how the CODM uses the reported measure of segment profit or loss to assess segment performance and allocate resources. The guidance is effective for fiscal years beginning after December 15, 2023 on an annual basis and beginning after December 15, 2024 on an interim basis. Early adoption is permitted. The adoption of this guidance will provide enhanced disclosures regarding reportable segments and will not have a material impact on the Company’s financial statements. |
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| Recently Adopted and Issued Accounting Guidance | Recently Adopted Accounting Guidance. On January 1, 2023, the Company adopted Accounting Standard Update (ASU) No. 2022-04 which requires a buyer in a supplier finance program to disclose qualitative and quantitative information about its supplier finance programs, including the key terms of the program, the amount of obligations outstanding at the end of the reporting period, a description of where those obligations are presented in the balance sheet, and effective January 1, 2024, a roll-forward of such amounts during the annual period. The adoption of this guidance resulted in enhanced disclosures regarding these programs (see Note V) and did not have a material impact on the Company's Consolidated Financial Statements. Recently Issued Accounting Guidance. In December 2023, the Financial Accounting Standards Board (FASB) issued ASU No. 2023-09 which includes changes to income tax disclosures, including greater disaggregation of information in the rate reconciliation and disclosure of taxes paid by jurisdiction. The guidance is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. The adoption of this guidance will provide enhanced disclosures regarding income taxes and will not have a material impact on the Company’s financial statements. In November 2023, the FASB issued ASU No. 2023-07 which requires disclosure of significant segment expenses regularly provided to the chief operating decision maker (CODM), other segment items (not included in significant segment expenses for each reportable segment), the title and position of the CODM, and an explanation of how the CODM uses the reported measure of segment profit or loss to assess segment performance and allocate resources. The guidance is effective for fiscal years beginning after December 15, 2023 on an annual basis and beginning after December 15, 2024 on an interim basis. Early adoption is permitted. The adoption of this guidance will provide enhanced disclosures regarding reportable segments and will not have a material impact on the Company’s financial statements. |
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Summary of Significant Accounting Policies (Tables) |
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| Accounting Policies [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||
| Weighted-Average Useful Lives of Structures and Machinery and Equipment | The following table details the weighted average useful lives of structures and machinery and equipment by type of operation (numbers in years):
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| Weighted-Average Useful Lives of Software and Other Intangible Assets | The following table details the weighted average useful lives of software and other intangible assets by type of operation (numbers in years):
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Restructuring and Other Charges, Net (Tables) |
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Restructuring and Related Activities [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Restructuring and Other Charges, Net | Restructuring and other charges, net were comprised of the following:
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| Schedule of Restructuring and Other Charges, Net by Reportable Segments, Pretax | Alcoa Corporation does not include Restructuring and other charges, net in the results of its reportable segments. The impact of allocating such charges to segment results would have been as follows:
(1)
Beginning in January 2023, the Company changed its operating segments, by combining the Bauxite and Alumina segments, and reported its financial results in the following two segments: (i) Alumina and (ii) Aluminum (see Note E). |
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| Activity and Reserve Balances for Restructuring Charges | Activity and reserve balances for restructuring charges were as follows:
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Segment and Related Information (Tables) |
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Segment Reporting [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Operating Results, Capital Expenditures and Assets of Alcoa's Reportable Segments | The operating results, capital expenditures, and assets of Alcoa Corporation’s reportable segments were as follows:
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| Schedule of Reconciliation of Certain Segment Information to Consolidated Totals | The following tables reconcile certain segment information to consolidated totals:
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| Schedule of Segment Adjusted EBITDA to Consolidated Net (Loss) Income Attributable to Alcoa Corporation |
(1) Transformation includes, among other items, the Adjusted EBITDA of previously closed operations. (2) Corporate expenses are composed of general administrative and other expenses of operating the corporate headquarters and other global administrative facilities, as well as research and development expenses of the corporate technical center. (3)
Other includes certain items that are not included in the Adjusted EBITDA of the reportable segments. |
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| Schedule of Segment Reporting Information to Consolidated Assets |
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| Schedule of Product Division Information | The following table represents the general commercial profile of the Company’s Bauxite, Alumina, and Primary aluminum product divisions (see text below table for Energy):
(1) API (Alumina Price Index) is a pricing mechanism that is calculated by the Company based on the weighted average of a prior month’s daily spot prices published by the following three indices: CRU Metallurgical Grade Alumina Price, Platts Metals Daily Alumina PAX Price, and FastMarkets Metal Bulletin Non-Ferrous Metals Alumina Index. (2) LME (London Metal Exchange) is a globally recognized exchange for commodity trading, including aluminum. The LME pricing component represents the underlying base metal component, based on quoted prices for aluminum on the exchange. The regional premium represents the incremental price over the base LME component that is associated with the physical delivery of metal to a particular region (e.g., the Midwest premium for metal sold in the United States). The product premium represents the incremental price for receiving physical metal in a particular shape or alloy. (3) CIF (cost, insurance, and freight) means that the Company pays for these items until the product reaches the buyer’s designated destination point related to transportation by vessel. DAP (delivered at place) means the same as CIF related to all methods of transportation. FOB (free on board) means that the Company pays for costs, insurance, and freight until the product reaches the seller’s designated shipping point. (4)
The net number of days means that the customer is required to remit payment to the Company for the invoice amount within the designated number of days. LC Sight is a letter of credit that is payable immediately (usually within five to ten business days) after a seller meets the requirements of the letter of credit (i.e. shipping documents that evidence the seller performed its obligations as agreed to with a buyer). CAD (cash against documents) is a payment arrangement in which a seller instructs a bank to provide shipping and title documents to the buyer at the time the buyer pays in full the accompanying bill of exchange. |
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| Schedule of Third-party Sales by Product Division | The following table details Alcoa Corporation’s Sales by product division:
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| Schedule of Geographic Information for Third-party Sales | Geographic information for Third-party sales was as follows (based upon the country where the point of sale originated):
(1) Sales of a portion of the alumina from refineries in Australia and Brazil and most of the aluminum from smelters in Canada occurred in the United States. (2) Sales of aluminum off-take related to an interest in the Saudi Arabia joint venture (see Note H), occurred in Spain through most of the third quarter of 2021, and in the United States thereafter. (3)
Sales of aluminum from smelters in Iceland and Norway occurred in Spain through most of the first quarter of 2021, and in the Netherlands thereafter. |
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| Schedule of Geographic Information for Long-Lived Assets | Geographic information for long-lived assets was as follows (based upon the physical location of the assets):
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Earnings Per Share (Tables) |
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Earnings Per Share [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Computation of Basic and Diluted EPS Attributable to Alcoa Corporation Common Shareholders | The share information used to compute basic and diluted EPS attributable to Alcoa Corporation common shareholders was as follows (shares in millions):
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Accumulated Other Comprehensive Loss (Tables) |
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary of Changes in Accumulated Other Comprehensive (Loss) Income by Component | The following table details the activity of the three components that comprise Accumulated other comprehensive loss for both Alcoa Corporation’s shareholders and Noncontrolling interest:
(1) These amounts were included in the computation of net periodic benefit cost for pension and other postretirement benefits. The amounts related to settlements and/or curtailments of certain pension and other postretirement benefits for Alcoa Corporation include $21, $633, and $952 for the years ended December 31, 2023, 2022, and 2021, respectively. The amounts related to settlements and/or curtailments of certain pension and other postretirement benefits for Noncontrolling interest include $0, ($1), and $25 for the years ended December 31, 2023, 2022, and 2021, respectively (see Note O). (2) These amounts were reported in Provision for income taxes on the accompanying Statement of Consolidated Operations. (3) These amounts were reported in Sales on the accompanying Statement of Consolidated Operations. (4) These amounts were reported in Cost of goods sold on the accompanying Statement of Consolidated Operations. (5) These amounts were included in Other (income) expenses, net on the accompanying Statement of Consolidated Operations. (6) In 2023, $5 was reported in Cost of goods sold and ($31) was reported in Sales on the accompanying Statement of Consolidated Operations. In 2022, $5 was reported in Cost of goods sold and ($10) was reported in Sales on the accompanying Statement of Consolidated Operations. (7)
A positive amount indicates a corresponding charge to earnings and a negative amount indicates a corresponding benefit to earnings. |
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Investments (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity Method Investments and Joint Ventures [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary of Investment |
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| Schedule of Equity Investment | The following table summarizes information of Alcoa Corporation’s equity investments as of December 31, 2023 and 2022.
The following table summarizes the profit and loss data for the respective periods ended December 31, as it relates to Alcoa Corporation’s equity investments. Information shown for the Saudi Arabia Joint Venture for all periods presented includes the combined balances for MAC and MBAC. The investments are grouped based on the nature of the investment. The Mining investments are part of the Alumina segment, while the Energy and Other investments are primarily part of the Aluminum segment.
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Inventories (Tables) |
12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Inventory Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Inventory Components |
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Properties, Plants, and Equipment, Net (Tables) |
12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Property, Plant and Equipment [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Properties, Plants, and Equipment, Net |
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Goodwill and Other Intangible Assets (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Goodwill and Intangible Assets Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary of Goodwill which is Included in Other Noncurrent Assets | Goodwill, which is included in Other noncurrent assets on the accompanying Consolidated Balance Sheet, was as follows:
The carrying value of Corporate’s goodwill is net of accumulated impairment losses of $742 as of both December 31, 2023 and 2022. As of December 31, 2023, the $142 of goodwill reflected in Corporate is allocated to Alcoa Corporation's Alumina reportable segment for purposes of impairment testing (see Note B). This goodwill is reflected in Corporate for segment reporting purposes because it is not included in management’s assessment of performance by the reportable segment. Changes in the carrying amount of goodwill were attributable to foreign currency translation as of December 31, 2023 and 2022. |
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| Other Intangible Assets | Other intangible assets, which are included in Other noncurrent assets on the accompanying Consolidated Balance Sheet, were as follows:
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Debt (Tables) |
12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Debt Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Short-term Borrowing | Short-term Borrowings.
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| Schedule of Long-Term Debt | Long-term Debt.
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Preferred and Common Stock (Tables) |
12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Activity for Stock Options and Stock Units | The activity for stock units and stock options during 2023 was as follows:
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Pension and Other Postretirement Benefits (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Summary of Information in Curtailment or Settlement of Benefits Requiring Remeasurement, Update to Discount Rates Used to Determine Benefit Obligations of Affected Plans | The following table presents certain information and the financial impacts of these actions on the accompanying Consolidated Financial Statements:
(1) This amount represents the net actuarial loss and was reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations. The following table presents certain information and the financial impacts of these actions on the accompanying Consolidated Financial Statements:
(1) Actions 1-4 caused interim plan remeasurements, including an update to the discount rates used to determine the benefit obligations of the affected plans. These amounts include impacts due to interim plan remeasurements. (2) These amounts represent the net actuarial loss (gain) and were reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations. The following table presents certain information and the financial impacts of these actions on the accompanying Consolidated Financial Statements:
(1)
These amounts primarily represent the accelerated amortization of a portion of the existing prior service benefit for curtailments and net actuarial loss for settlements and were reclassified from Accumulated other comprehensive loss to Restructuring and other charges, net (see Note D) on the accompanying Statement of Consolidated Operations. |
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| Schedule of Obligations and Funded Status | Obligations and Funded Status
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| Schedule of Pension Plan Benefit Obligations | Pension Plan Benefit Obligations
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| Components of Net Periodic Benefit Cost | Components of Net Periodic Benefit Cost
(1) In 2023, 2022, and 2021, net periodic benefit cost for U.S pension plans was $6, $698, and $962, respectively. (2) These amounts were reported in Other expenses (income), net on the accompanying Statement of Consolidated Operations. (3) These amounts were reported in Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note D). In 2023, 2022 and 2021, settlements were due to management actions (see Plan Actions above). (4) These amounts were reported in Restructuring and other charges, net on the accompanying Statement of Consolidated Operations (see Note D). In 2021, curtailments were due to management actions (see Plan Actions above). (5)
Amounts attributed to joint venture partners are not included. |
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| Schedule of Assumed Health Care Cost Trend Rates | Assumed health care cost trend rates for U.S. other postretirement benefit plans were as follows (non-U.S. plans are not material):
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| Schedule of Pension and Postretirement Plans Weighted Average Target and Actual Asset Allocations | Plan Assets. Alcoa’s pension plan weighted average target and actual asset allocations at December 31, 2023 and 2022, by asset class, were as follows:
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| Schedule of Fair Value of Pension Plan Assets | The following table presents the fair value of pension plan assets classified under either the appropriate level of the fair value hierarchy or net asset value:
(1) As of December 31, 2023, the total fair value of pension plan assets excludes a net receivable of $13, which primarily represents securities not yet settled plus interest and dividends earned on various investments. (2)
As of December 31, 2022, the total fair value of pension plan assets excludes a net receivable of $8, which primarily represents securities not yet settled plus interest and dividends earned on various investments. |
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| Schedule of Benefit Payments Expected to be Paid | Benefit payments expected to be paid to pension and other postretirement benefit plan participants are as follows:
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| Benefit Obligation [Member] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Weighted Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost | Weighted average assumptions used to determine benefit obligations for pension and other postretirement benefit plans were as follows:
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| Net Periodic Benefit Cost [Member] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Weighted Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost | Weighted average assumptions used to determine net periodic benefit cost for pension and other postretirement benefit plans were as follows:
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Derivatives and Other Financial Instruments (Tables) |
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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):
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| Schedule of Outstanding Quantities of Derivative Instruments | The following table presents the outstanding quantities of derivative instruments classified as Level 1:
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| 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:
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| 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):
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| 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:
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| 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:
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| Schedule of Reconciliation of Activity for Derivative Contracts | The following tables present a reconciliation of activity for Level 3 derivative instruments:
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| 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:
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Income Taxes (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Income Tax Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Components of (Loss) income from Continuing Operations Before Income Taxes | The components of (Loss) income before income taxes were as follows:
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| Schedule of Provision for Income Taxes on Income from Continuing Operations | Provision for income taxes consisted of the following:
Federal includes U.S. income taxes related to foreign income. |
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| Reconciliation of U.S. Federal Statutory Rate to Alcoa's Effective Tax Rate | A reconciliation of the U.S. federal statutory rate to Alcoa’s effective tax rate was as follows:
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| Schedule of Components of Net Deferred Tax Assets and Liabilities | The components of deferred tax assets and liabilities based on the underlying attributes without regard to jurisdiction were as follows:
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| Schedule of Expiration Periods of Deferred Tax Assets | The following table details the expiration periods of the deferred tax assets presented above:
Deferred tax assets with no expiration may still have annual limitations on utilization. Other represents deferred tax assets whose expiration is dependent upon the reversal of the underlying temporary difference. |
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| Composition of Net Deferred Tax Asset by Jurisdiction | The total deferred tax asset (net of valuation allowance) is supported by projections of future taxable income exclusive of reversing temporary differences and taxable temporary differences that reverse within the carryforward period. The composition of Alcoa’s net deferred tax asset by jurisdiction as of December 31, 2023 was as follows:
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| Schedule of Changes in Valuation Allowance | The following table details the changes in the valuation allowance:
(1) Reflects valuation allowances initially established as a result of a change in management’s judgment regarding the realizability of deferred tax assets. (2)
Reflects movements in previously established valuation allowances, which increase or decrease as the related deferred tax assets increase or decrease. Such movements occur as a result of a change in management’s judgment regarding previously established valuation allowances, remeasurement due to a tax rate change and changes in the underlying attributes of the deferred tax assets, including expiration of the attribute and reversal of the temporary difference that gave rise to the deferred tax asset. |
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| Reconciliation of Unrecognized Tax Benefits (Excluding Interest and Penalties) | The reserve balance for unrecognized tax benefits is included in Noncurrent income taxes on the Consolidated Balance Sheet. A reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding interest and penalties) was as follows:
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Asset Retirement Obligations (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Asset Retirement Obligation Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Carrying Value of Recorded AROs by Major Category | The following table details the carrying value of recorded AROs by major category, of which $217 and $117 was classified as a current liability as of December 31, 2023 and 2022, respectively:
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| Schedule of Changes in Carrying Value of Recorded AROs | The following table details the changes in the total carrying value of recorded AROs:
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| Schedule of Estimated Timing of Cash Outflows on Asset Retirement Obligations | The estimated timing of cash outflows for recorded AROs at December 31, 2023 was as follows:
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Contingencies and Commitments (Tables) |
12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2023 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Commitments and Contingencies Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Changes in Carrying Value of Recorded Environmental Remediation Reserves | Alcoa Corporation’s environmental remediation reserve balance reflects the most probable costs to remediate identified environmental conditions for which costs can be reasonably estimated. The following table details the changes in the carrying value of recorded environmental remediation reserves:
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| Schedule of Estimate Timing of Cash Outflows from Environmental Reserves | The estimated timing of cash outflows from the environmental remediation reserve at December 31, 2023 was as follows:
|
Leasing (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Leases [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Lease Expense and Operating Cash Flows | Lease expense and operating cash flows include:
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| Schedule of Weighted Average Lease Term and Weighted Average Discount Rate | The weighted average lease term and weighted average discount rate were as follows:
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| Schedule of Aggregate Right-of Use Assets and Related Lease Obligations | The following represents the aggregate right-of-use assets and related lease obligations recognized in the Consolidated Balance Sheet:
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| Schedule of Future Cash Flows Related to Operating Lease Obligations | The future cash flows related to the operating lease obligations as of December 31, 2023 were as follows:
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Other Financial Information (Tables) |
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2023 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other Financial Information [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Interest Cost Components | Interest Cost Components
|
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| Schedule of Other Expenses (Income), Net | Other Expenses (Income), Net
|
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| Schedule of Other Noncurrent Assets | Other Noncurrent Assets
|
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| Schedule of Other Noncurrent Liabilities and Deferred Credits | Other Noncurrent Liabilities and Deferred Credits
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| Schedule of Cash and Cash Equivalents and Restricted Cash | Cash and Cash Equivalents and Restricted Cash
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| Schedule of Cash Paid for Interest and Income Taxes | Cash Flow Information Cash paid for interest and income taxes was as follows:
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Restructuring and Other Charges, Net - Schedule of Restructuring and Other Charges, Net (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Restructuring and Related Activities [Abstract] | |||
| Settlements and/or curtailments related to retirement benefits | $ 21 | $ 632 | $ 977 |
| Severance and employee termination costs | 11 | 1 | 1 |
| Loss on divestitures | 79 | ||
| Asset impairments | 50 | 58 | 75 |
| Asset retirement obligations | 41 | 34 | 23 |
| Environmental remediation | 27 | 21 | 15 |
| Other | 36 | (7) | 82 |
| Reversals of previously recorded charges | (2) | (122) | (45) |
| Restructuring and other charges, net | $ 184 | $ 696 | $ 1,128 |
Restructuring and Other Charges, Net - Schedule of Restructuring and Other Charges, Net by Reportable Segments, Pretax (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring and other charges, net | $ 184 | $ 696 | $ 1,128 |
| Operating Segments [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring and other charges, net | 177 | 55 | 185 |
| Corporate [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring and other charges, net | 7 | 641 | 943 |
| Alumina [Member] | Operating Segments [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring and other charges, net | 8 | (27) | 1 |
| Aluminum Segment [Member] | Operating Segments [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring and other charges, net | $ 169 | $ 82 | $ 184 |
Restructuring and Other Charges, Net - Activity and Reserve Balances for Restructuring Charges (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring reserve beginning balance | $ 117 | $ 93 | $ 63 |
| Restructuring and other charges, net | 66 | 74 | 81 |
| Cash payments | (124) | (39) | (29) |
| Reversals and other | 4 | (11) | (22) |
| Restructuring reserve ending balance | 63 | 117 | 93 |
| Severance and Employee Termination Costs [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring reserve beginning balance | 1 | 3 | 6 |
| Restructuring and other charges, net | 11 | 1 | 1 |
| Cash payments | (6) | (2) | (4) |
| Reversals and other | (1) | ||
| Restructuring reserve ending balance | 6 | 1 | 3 |
| Other Costs [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Restructuring reserve beginning balance | 116 | 90 | 57 |
| Restructuring and other charges, net | 55 | 73 | 80 |
| Cash payments | (118) | (37) | (25) |
| Reversals and other | 4 | (10) | (22) |
| Restructuring reserve ending balance | $ 57 | $ 116 | $ 90 |
Restructuring and Other Charges, Net - Additional Information (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Restructuring Cost and Reserve [Line Items] | ||
| Noncurrent portion of the reserve | $ 15 | $ 3 |
| Alcoa Corporation [Member] | ||
| Restructuring Cost and Reserve [Line Items] | ||
| Noncurrent portion of the reserve | $ 15 | $ 3 |
Segment and Related Information - Additional Information (Detail) |
12 Months Ended |
|---|---|
|
Dec. 31, 2023
Segment
Product_Division
| |
| Segment Reporting Information [Line Items] | |
| Number of operating segments | Segment | 2 |
| Number of product divisions | Product_Division | 4 |
| Alcoa Corporation [Member] | |
| Segment Reporting Information [Line Items] | |
| Ownership interest in joint venture | 25.10% |
| AWAC [Member] | |
| Segment Reporting Information [Line Items] | |
| Ownership interest in joint venture | 25.10% |
Segment and Related Information - Schedule of Reconciliation of Certain Segment Information to Consolidated Totals (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Segment Reporting, Revenue Reconciling Item [Line Items] | |||
| Consolidated sales | $ 10,551 | $ 12,451 | $ 12,152 |
| Other [Member] | |||
| Segment Reporting, Revenue Reconciling Item [Line Items] | |||
| Consolidated sales | 13 | (8) | 11 |
| Operating Segments [Member] | |||
| Segment Reporting, Revenue Reconciling Item [Line Items] | |||
| Consolidated sales | 12,201 | 14,194 | 13,711 |
| Intersegment Eliminations [Member] | |||
| Segment Reporting, Revenue Reconciling Item [Line Items] | |||
| Elimination of intersegment sales | $ (1,663) | $ (1,735) | $ (1,570) |
Segment and Related Information - Schedule of Segment Reporting Information to Consolidated Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Schedule Of Assets By Segment [Line Items] | ||
| Consolidated assets | $ 14,155 | $ 14,756 |
| Cash and cash equivalents | 944 | 1,363 |
| Corporate fixed assets, net | 6,785 | 6,493 |
| Corporate goodwill | 146 | 145 |
| Deferred income taxes | 333 | 296 |
| Operating Segments [Member] | ||
| Schedule Of Assets By Segment [Line Items] | ||
| Consolidated assets | 12,007 | 12,217 |
| Intersegment Eliminations [Member] | ||
| Schedule Of Assets By Segment [Line Items] | ||
| Elimination of intersegment receivables | 159 | 126 |
| Other [Member] | ||
| Schedule Of Assets By Segment [Line Items] | ||
| Cash and cash equivalents | 944 | 1,363 |
| Corporate fixed assets, net | 392 | 364 |
| Corporate goodwill | 142 | 141 |
| Deferred income taxes | 333 | 296 |
| Pension assets | 125 | 146 |
| Other | $ 371 | $ 355 |
Segment and Related Information - Schedule of Third-party Sales by Product Division (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Disaggregation Of Revenue [Line Items] | |||
| Sales | $ 10,551 | $ 12,451 | $ 12,152 |
| Primary Aluminum [Member] | |||
| Disaggregation Of Revenue [Line Items] | |||
| Sales | 7,045 | 8,887 | 8,420 |
| Alumina [Member] | |||
| Disaggregation Of Revenue [Line Items] | |||
| Sales | 3,103 | 3,478 | 3,125 |
| Flat-Rolled Aluminum [Member] | |||
| Disaggregation Of Revenue [Line Items] | |||
| Sales | 320 | ||
| Energy [Member] | |||
| Disaggregation Of Revenue [Line Items] | |||
| Sales | 118 | 201 | 286 |
| Bauxite [Member] | |||
| Disaggregation Of Revenue [Line Items] | |||
| Sales | 466 | 168 | 207 |
| Other Products [Member] | |||
| Disaggregation Of Revenue [Line Items] | |||
| Sales | $ (181) | $ (283) | $ (206) |
Earnings Per Share - Schedule of Computation of Basic and Diluted EPS Attributable to Alcoa Corporation Common Shareholders (Detail) - shares shares in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Earnings Per Share [Abstract] | |||
| Average shares outstanding—basic | 178 | 181 | 186 |
| Effect of dilutive securities: | |||
| Stock units | 4 | ||
| Average shares outstanding—diluted | 178 | 181 | 190 |
Earnings Per Share - Additional Information (Detail) - $ / shares shares in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Stock Awards and Stock Options [Member] | |||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
| Common shares equivalents that would have been included in diluted average shares outstanding | 3 | 3 | |
| Number of anti-dilutive securities | 3 | 5 | |
| Stock Options [Member] | |||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
| Weighted average exercise price of options | $ 38.67 | ||
Investments - Summary of Investment (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Schedule of Investments [Abstract] | ||
| Equity investments | $ 969 | $ 1,112 |
| Other investments | 10 | 10 |
| Investments | $ 979 | $ 1,122 |
Receivables - Additional Information (Detail) - Receivables Purchase Agreement [Member] - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Aug. 27, 2023 |
Jan. 31, 2023 |
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Unsold customer receivables as collateral sold receivables | $ 104 | ||
| Sale of gross customer receivables | 591 | ||
| Reinvested collections from previously sold receivables | 477 | ||
| Cash proceeds from financial institution | 114 | ||
| Maximum [Member] | |||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Receivables previously secured by credit facility | $ 130 | $ 150 | |
| Accounts Payable [Member] | |||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Cash collections from previously sold receivables yet to be reinvested | $ 99 |
Inventories - Schedule of Inventory Components (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Inventory Disclosure [Abstract] | ||
| Finished goods | $ 355 | $ 385 |
| Work-in-process | 287 | 350 |
| Bauxite and alumina | 586 | 584 |
| Purchased raw materials | 700 | 923 |
| Operating supplies | 230 | 185 |
| Inventories, total | $ 2,158 | $ 2,427 |
Goodwill and Other Intangible Assets - Summary of Goodwill which is Included in Other Noncurret Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Goodwill [Line Items] | ||
| Goodwill | $ 146 | $ 145 |
| Other Noncurrent Assets [Member] | ||
| Goodwill [Line Items] | ||
| Goodwill | 146 | 145 |
| Alumina [Member] | Other Noncurrent Assets [Member] | ||
| Goodwill [Line Items] | ||
| Goodwill | 4 | 4 |
| Corporate Segment [Member] | Other Noncurrent Assets [Member] | ||
| Goodwill [Line Items] | ||
| Goodwill | $ 142 | $ 141 |
Goodwill and Other Intangible Assets - Summary of Goodwill which is Included in Other Noncurret Assets (Parenthetical) (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Goodwill [Line Items] | ||
| Goodwill | $ 146 | $ 145 |
| Other Noncurrent Assets [Member] | ||
| Goodwill [Line Items] | ||
| Goodwill | 146 | 145 |
| Corporate Segment [Member] | ||
| Goodwill [Line Items] | ||
| Accumulated impairment losses | 742 | 742 |
| Corporate Segment [Member] | Other Noncurrent Assets [Member] | ||
| Goodwill [Line Items] | ||
| Goodwill | 142 | 141 |
| Alumina [Member] | Other Noncurrent Assets [Member] | ||
| Goodwill [Line Items] | ||
| Goodwill | $ 4 | $ 4 |
Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Goodwill And Intangible Assets [Line Items] | |||
| Amortization expense related to the intangible assets | $ 5,000,000 | $ 7,000,000 | $ 11,000,000 |
| Expected amortization for the year 2024 | 10,000,000 | ||
| Expected amortization for the year 2025 | 10,000,000 | ||
| Expected amortization for the year 2026 | 10,000,000 | ||
| Expected amortization for the year 2027 | 10,000,000 | ||
| Expected amortization for the year 2028 | 10,000,000 | ||
| Alumina [Member] | |||
| Goodwill And Intangible Assets [Line Items] | |||
| Goodwill impairment | $ 0 | ||
Debt - Schedule of Short-term Borrowing (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Debt Disclosure [Abstract] | ||
| Short-term borrowings | $ 56 | $ 0 |
Debt - Schedule of Long-Term Debt (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| Unamortized discounts and deferred financing costs | $ (21) | $ (27) |
| Total | 1,811 | 1,807 |
| Less: amount due within one year | 79 | 1 |
| Long-term debt, less amount due within one year | 1,732 | 1,806 |
| 5.500% Notes, due 2027 [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term debt | 750 | 750 |
| 6.125% Notes, due 2028 [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term debt | 500 | 500 |
| 4.125% Notes, due 2029 [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term debt | 500 | 500 |
| Other [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term debt | $ 82 | $ 84 |
Debt - Principal maturities of long-term debt - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Debt Instrument [Line Items] | ||
| Principal amount of long-term debt maturing in year 2024 | $ 79 | |
| Principal amount of long-term debt maturing in year 2025 | 1 | |
| Principal amount of long-term debt maturing in year 2026 | 1 | |
| Principal amount of long-term debt maturing in year 2027 | 750 | |
| Principal amount of long-term debt maturing in year 2028 | 500 | |
| Other [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term debt | 82 | $ 84 |
| Other [Member] | Term Loan [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term debt | $ 78 | |
| Long term debt extended month and year | 2024-11 |
Pension and Other Postretirement Benefits - Summary of Information in Curtailment or Settlement of Benefits Requiring Remeasurement, Update to Discount Rates Used to Determine Benefit Obligations of Affected Plans (Detail) $ in Millions |
3 Months Ended | 12 Months Ended | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Sep. 30, 2023
USD ($)
|
Jun. 30, 2023
USD ($)
|
Dec. 31, 2022
USD ($)
Employees
|
Sep. 30, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
Employees
|
Sep. 30, 2021
USD ($)
|
Dec. 31, 2023
USD ($)
Employees
|
Dec. 31, 2022
USD ($)
Employees
|
Dec. 31, 2021
USD ($)
Employees
|
Apr. 30, 2023 |
Mar. 31, 2023 |
Jul. 31, 2022 |
Nov. 30, 2021 |
Jun. 30, 2021 |
Mar. 31, 2021 |
Dec. 31, 2020 |
|
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Increase (decrease) to other noncurrent assets | $ 210 | $ 87 | $ 160 | |||||||||||||
| Action# 1 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 370 | |||||||||||||||
| Weighted average discount rate | 5.58% | 5.20% | ||||||||||||||
| Plan remeasurement date | Mar. 31, 2023 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 15 | $ 15 | ||||||||||||||
| Decrease to accrued other postretirement benefits | (9) | $ (9) | ||||||||||||||
| Action# 2 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 530 | |||||||||||||||
| Weighted average discount rate | 5.20% | 4.80% | ||||||||||||||
| Plan remeasurement date | Apr. 30, 2023 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | 22 | $ 22 | ||||||||||||||
| Increase (decrease) to other noncurrent assets | (5) | (5) | ||||||||||||||
| Settlement loss (gain) | $ (21) | $ 21 | ||||||||||||||
| Action# 3 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 50 | |||||||||||||||
| Weighted average discount rate | 5.03% | 5.08% | ||||||||||||||
| Plan remeasurement date | Sep. 30, 2023 | |||||||||||||||
| Increase (decrease) to other noncurrent assets | $ (2) | $ (2) | ||||||||||||||
| 2023 Plan Actions [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 950 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 37 | |||||||||||||||
| Increase (decrease) to other noncurrent assets | (7) | |||||||||||||||
| Decrease to accrued other postretirement benefits | (9) | |||||||||||||||
| Settlement loss (gain) | $ 21 | |||||||||||||||
| Action# 1 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 4,400 | 4,400 | ||||||||||||||
| Weighted average discount rate | 2.90% | 2.90% | 4.63% | |||||||||||||
| Plan remeasurement date | Jul. 31, 2022 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 5 | $ 5 | ||||||||||||||
| Increase (decrease) to other noncurrent assets | 27 | 27 | ||||||||||||||
| Settlement loss (gain) | (617) | $ 617 | ||||||||||||||
| Action# 2 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 45 | 45 | ||||||||||||||
| Weighted average discount rate | 2.90% | 2.90% | 4.63% | |||||||||||||
| Plan remeasurement date | Jul. 31, 2022 | |||||||||||||||
| Settlement loss (gain) | $ (11) | $ 11 | ||||||||||||||
| Action# 3 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 5 | 5 | ||||||||||||||
| Weighted average discount rate | 4.57% | 5.71% | 4.57% | |||||||||||||
| Plan remeasurement date | Sep. 30, 2022 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 23 | $ 23 | ||||||||||||||
| Increase (decrease) to other noncurrent assets | (12) | (12) | ||||||||||||||
| Settlement loss (gain) | $ (1) | $ 1 | ||||||||||||||
| Action# 4 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 25 | 25 | ||||||||||||||
| Weighted average discount rate | 2.46% | 4.99% | 2.46% | |||||||||||||
| Plan remeasurement date | Sep. 30, 2022 | |||||||||||||||
| Increase (decrease) to other noncurrent assets | $ 21 | $ 21 | ||||||||||||||
| Settlement loss (gain) | $ 3 | $ (3) | ||||||||||||||
| Action# 5 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 20 | 20 | ||||||||||||||
| Plan remeasurement date | Dec. 31, 2022 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 3 | $ 3 | ||||||||||||||
| Settlement loss (gain) | $ (6) | $ 6 | ||||||||||||||
| 2022 Plan Actions [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 4,495 | 4,495 | ||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 31 | |||||||||||||||
| Increase (decrease) to other noncurrent assets | 36 | |||||||||||||||
| Settlement loss (gain) | $ 632 | |||||||||||||||
| Action# 1 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 840 | 840 | ||||||||||||||
| Weighted average discount rate | 3.06% | 2.45% | ||||||||||||||
| Plan remeasurement date | Mar. 31, 2021 | |||||||||||||||
| Decrease to accrued other postretirement benefits | $ (106) | |||||||||||||||
| Curtailment loss(gain) | 17 | |||||||||||||||
| Settlement loss (gain) | $ 26 | |||||||||||||||
| Action# 2 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 120 | 120 | ||||||||||||||
| Weighted average discount rate | 2.71% | 2.38% | ||||||||||||||
| Plan remeasurement date | Jun. 30, 2021 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ (90) | |||||||||||||||
| Settlement loss (gain) | $ 39 | |||||||||||||||
| Action# 3 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 20 | 20 | ||||||||||||||
| Weighted average discount rate | 2.74% | 2.71% | ||||||||||||||
| Plan remeasurement date | Sep. 30, 2021 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ 7 | $ 7 | ||||||||||||||
| Settlement loss (gain) | $ (7) | $ 7 | ||||||||||||||
| Action# 4 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 20 | 20 | ||||||||||||||
| Weighted average discount rate | 1.53% | 1.34% | ||||||||||||||
| Plan remeasurement date | Sep. 30, 2021 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ (38) | $ (38) | ||||||||||||||
| Settlement loss (gain) | $ (1) | $ 1 | ||||||||||||||
| Action# 5 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 800 | 800 | ||||||||||||||
| Settlement loss (gain) | $ (63) | $ 63 | ||||||||||||||
| Action# 6 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 14,000 | 14,000 | ||||||||||||||
| Weighted average discount rate | 2.79% | 2.59% | ||||||||||||||
| Plan remeasurement date | Nov. 30, 2021 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ (84) | $ (84) | ||||||||||||||
| Settlement loss (gain) | $ (848) | $ 848 | ||||||||||||||
| Action# 7 [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Number of affected plan participants | Employees | 60 | 60 | ||||||||||||||
| Weighted average discount rate | 2.79% | 2.59% | ||||||||||||||
| Plan remeasurement date | Nov. 30, 2021 | |||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | $ (1) | $ (1) | ||||||||||||||
| Settlement loss (gain) | $ (10) | 10 | ||||||||||||||
| 2021 Plan Actions [Member] | ||||||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||
| Increase (decrease) to accrued other pension benefits liability | (206) | |||||||||||||||
| Decrease to accrued other postretirement benefits | (106) | |||||||||||||||
| Curtailment loss(gain) | 17 | |||||||||||||||
| Settlement loss (gain) | $ 994 | |||||||||||||||
Pension and Other Postretirement Benefits - Schedule of Obligations and Funded Status (Detail) - USD ($) |
12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||
| Fair value of plan assets at beginning of year | $ 2,426,000,000 | ||||||||
| Employer contributions | 0 | $ 0 | $ 500,000,000 | ||||||
| Fair value of plan assets at end of year | 2,206,000,000 | 2,426,000,000 | |||||||
| Pension Benefits [Member] | |||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||
| Benefit obligation at beginning of year | 2,518,000,000 | ||||||||
| Service cost | [1] | 10,000,000 | 13,000,000 | 22,000,000 | |||||
| Interest cost | [1],[2] | 114,000,000 | 104,000,000 | 116,000,000 | |||||
| Settlements | [1],[3] | 21,000,000 | 632,000,000 | 968,000,000 | |||||
| Benefit obligation at end of year | 2,393,000,000 | 2,518,000,000 | |||||||
| Funded status | (174,000,000) | 84,000,000 | |||||||
| Less: Amounts attributed to joint venture partners | (11,000,000) | (6,000,000) | |||||||
| Net funded status | (163,000,000) | 78,000,000 | |||||||
| Noncurrent assets | 125,000,000 | 146,000,000 | |||||||
| Current liabilities | (10,000,000) | (11,000,000) | |||||||
| Noncurrent liabilities | (278,000,000) | (213,000,000) | |||||||
| Net amount recognized | (163,000,000) | (78,000,000) | |||||||
| Net actuarial loss (benefit) | 1,098,000,000 | 1,016,000,000 | |||||||
| Prior service cost (benefit) | 4,000,000 | 2,000,000 | |||||||
| Total, before tax effect | 1,102,000,000 | 1,018,000,000 | |||||||
| Less: Amounts attributed to joint venture partners | 33,000,000 | 27,000,000 | |||||||
| Net amount recognized, before tax effect | 1,069,000,000 | 991,000,000 | |||||||
| Net actuarial loss (benefit) | 131,000,000 | (141,000,000) | |||||||
| Amortization of accumulated net actuarial (loss) benefit | (49,000,000) | (720,000,000) | |||||||
| Prior service cost | 2,000,000 | ||||||||
| Total, before tax effect | 84,000,000 | (861,000,000) | |||||||
| Less: Amounts attributed to joint venture partners | 6,000,000 | (11,000,000) | |||||||
| Net amount recognized, before tax effect | 78,000,000 | (850,000,000) | |||||||
| Pension Benefits [Member] | Change In Benefit Obligation [Member] | |||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||
| Benefit obligation at beginning of year | 2,518,000,000 | 4,594,000,000 | |||||||
| Service cost | 11,000,000 | 13,000,000 | |||||||
| Interest cost | 119,000,000 | 107,000,000 | |||||||
| Amendments | 2,000,000 | ||||||||
| Actuarial losses (gains) | 117,000,000 | (803,000,000) | |||||||
| Settlements | (280,000,000) | (1,090,000,000) | |||||||
| Benefits paid | (133,000,000) | (211,000,000) | |||||||
| Suriname resident election transfer | 12,000,000 | ||||||||
| Foreign currency translation impact | 27,000,000 | (92,000,000) | |||||||
| Benefit obligation at end of year | 2,393,000,000 | 2,518,000,000 | 4,594,000,000 | ||||||
| Pension Benefits [Member] | Change In Plan Assets [Member] | |||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||
| Settlements | (280,000,000) | (1,090,000,000) | |||||||
| Benefits paid | (125,000,000) | (204,000,000) | |||||||
| Foreign currency translation impact | 24,000,000 | (88,000,000) | |||||||
| Fair value of plan assets at beginning of year | 2,434,000,000 | 4,306,000,000 | |||||||
| Actual return on plan assets | 141,000,000 | (528,000,000) | |||||||
| Employer contributions | 24,000,000 | 18,000,000 | |||||||
| Participant contributions | 3,000,000 | 4,000,000 | |||||||
| Administrative expenses | (9,000,000) | (6,000,000) | |||||||
| Fair value of plan assets at end of year | 2,219,000,000 | 2,434,000,000 | 4,306,000,000 | ||||||
| Annuity purchase premium refund | 7,000,000 | 22,000,000 | |||||||
| Other Postretirement Benefits [Member] | |||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||
| Service cost | 3,000,000 | 4,000,000 | 4,000,000 | ||||||
| Interest cost | [2] | 26,000,000 | 15,000,000 | 15,000,000 | |||||
| Settlements | [3] | 26,000,000 | |||||||
| Funded status | (494,000,000) | 536,000,000 | |||||||
| Net funded status | (494,000,000) | 536,000,000 | |||||||
| Current liabilities | (51,000,000) | (55,000,000) | |||||||
| Noncurrent liabilities | (443,000,000) | (481,000,000) | |||||||
| Net amount recognized | (494,000,000) | (536,000,000) | |||||||
| Net actuarial loss (benefit) | 88,000,000 | 95,000,000 | |||||||
| Prior service cost (benefit) | (97,000,000) | (111,000,000) | |||||||
| Total, before tax effect | (9,000,000) | (16,000,000) | |||||||
| Net amount recognized, before tax effect | (9,000,000) | (16,000,000) | |||||||
| Net actuarial loss (benefit) | (2,000,000) | (140,000,000) | |||||||
| Amortization of accumulated net actuarial (loss) benefit | (5,000,000) | (18,000,000) | |||||||
| Amortization of prior service benefit | 14,000,000 | 14,000,000 | |||||||
| Total, before tax effect | 7,000,000 | (144,000,000) | |||||||
| Net amount recognized, before tax effect | 7,000,000 | (144,000,000) | |||||||
| Other Postretirement Benefits [Member] | Change In Benefit Obligation [Member] | |||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||
| Benefit obligation at beginning of year | 536,000,000 | 710,000,000 | |||||||
| Service cost | 3,000,000 | 4,000,000 | |||||||
| Interest cost | 26,000,000 | 15,000,000 | |||||||
| Actuarial losses (gains) | (7,000,000) | (140,000,000) | |||||||
| Benefits paid | (52,000,000) | (53,000,000) | |||||||
| Suriname resident election transfer | (12,000,000) | ||||||||
| Benefit obligation at end of year | $ 494,000,000 | $ 536,000,000 | $ 710,000,000 | ||||||
| |||||||||
Pension and Other Postretirement Benefits - Schedule of Pension Plan Benefit Obligations (Detail) - Pension Benefits [Member] - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Projected benefit obligation | $ 2,393 | $ 2,518 |
| Accumulated benefit obligation | 2,285 | 2,453 |
| Projected benefit obligation | 1,636 | 1,465 |
| Fair value of plan assets | 1,336 | 1,232 |
| Accumulated benefit obligation | 1,425 | 1,458 |
| Fair value of plan assets | $ 1,169 | $ 1,232 |
Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions |
12 Months Ended | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|||||||||||
| Pension Benefits [Member] | |||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||||
| Service cost | [1] | $ 10 | $ 13 | $ 22 | |||||||||
| Interest cost | [1],[2] | 114 | 104 | 116 | |||||||||
| Expected return on plan assets | [1],[2] | (146) | (151) | (281) | |||||||||
| Recognized net actuarial loss | [1],[2] | 28 | 88 | 190 | |||||||||
| Settlements | [1],[3] | 21 | 632 | 968 | |||||||||
| Net periodic benefit cost | [1],[4] | 27 | 686 | 1,015 | |||||||||
| Other Postretirement Benefits [Member] | |||||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||||
| Service cost | 3 | 4 | 4 | ||||||||||
| Interest cost | [2] | 26 | 15 | 15 | |||||||||
| Recognized net actuarial loss | [2] | 5 | 18 | 21 | |||||||||
| Amortization of prior service cost (benefit) | [2] | (14) | (14) | (14) | |||||||||
| Settlements | [3] | 26 | |||||||||||
| Curtailment charge (gain) | [5] | (17) | |||||||||||
| Net periodic benefit cost | [4] | $ 20 | $ 23 | $ 35 | |||||||||
| |||||||||||||
Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Parenthetical) (Detail) - Pension Benefits [Member] - USD ($) $ in Millions |
12 Months Ended | ||||||
|---|---|---|---|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||
| Net periodic benefit cost | [1],[2] | $ 27 | $ 686 | $ 1,015 | |||
| United States [Member] | |||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||
| Net periodic benefit cost | $ 6 | $ 698 | $ 962 | ||||
| |||||||
Pension and Other Postretirement Benefits - Schedule of Weighted Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost (Detail) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Pension Benefits [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Discount rate | 5.03% | 5.41% | |
| Rate of compensation increase | 3.77% | 3.21% | |
| Discount rate | 5.34% | 2.66% | 1.91% |
| Expected long-term rate of return on plan assets | 6.21% | 4.94% | 5.66% |
| Rate of compensation increase | 3.21% | 3.11% | 2.58% |
| Other Postretirement Benefits [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Discount rate | 5.19% | 5.54% | |
| Discount rate | 5.45% | 2.46% | 1.99% |
Pension and Other Postretirement Benefits - Schedule of Assumed Health Care Cost Trend Rates (Detail) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Retirement Benefits [Abstract] | |||
| Health care cost trend rate assumed for next year | 6.50% | 7.00% | 5.50% |
| Rate to which the cost trend rate gradually declines | 5.00% | 5.00% | 4.50% |
| Year that the rate reaches the rate at which it is assumed to remain | 2032 | 2028 | 2026 |
Pension and Other Postretirement Benefits - Schedule of Pension and Postretirement Plans Weighted Average Target and Actual Asset Allocations (Detail) |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 100.00% | 100.00% |
| Plan Assets [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 100.00% | 100.00% |
| Equities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 20.00% | 20.00% |
| Fixed Income Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 65.00% | 65.00% |
| Fixed Income Securities [Member] | Plan Assets [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 70.00% | 57.00% |
| Other Investments [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 15.00% | 15.00% |
| Other Investments [Member] | Plan Assets [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 13.00% | 14.00% |
| Equity Securities [Member] | Plan Assets [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plan, asset allocations | 17.00% | 29.00% |
Pension and Other Postretirement Benefits - Schedule of Fair Value of Pension Plan Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | $ 2,206 | $ 2,426 |
| Equities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 369 | 704 |
| Equity Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 242 | 551 |
| Long/Short Equity Hedge Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 8 | |
| Private Equity [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 127 | 145 |
| Fixed Income Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 1,544 | 1,392 |
| Intermediate and Long Duration Government Credit [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 1,416 | 1,236 |
| Cash and Cash Equivalent Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 128 | 156 |
| Other Investments [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 293 | 330 |
| Real Estate Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 274 | 302 |
| Other Investments, Other [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 19 | 28 |
| Level 1 [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 546 | 519 |
| Level 1 [Member] | Equities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 108 | 71 |
| Level 1 [Member] | Equity Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 108 | 71 |
| Level 1 [Member] | Fixed Income Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 417 | 428 |
| Level 1 [Member] | Intermediate and Long Duration Government Credit [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 403 | 390 |
| Level 1 [Member] | Cash and Cash Equivalent Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 14 | 38 |
| Level 1 [Member] | Other Investments [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 21 | 20 |
| Level 1 [Member] | Real Estate Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 21 | 20 |
| Level 2 [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 517 | 426 |
| Level 2 [Member] | Fixed Income Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 517 | 426 |
| Level 2 [Member] | Intermediate and Long Duration Government Credit [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 517 | 426 |
| Net Asset Value [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 1,143 | 1,481 |
| Net Asset Value [Member] | Equities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 261 | 633 |
| Net Asset Value [Member] | Equity Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 134 | 480 |
| Net Asset Value [Member] | Long/Short Equity Hedge Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 8 | |
| Net Asset Value [Member] | Private Equity [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 127 | 145 |
| Net Asset Value [Member] | Fixed Income Securities [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 610 | 538 |
| Net Asset Value [Member] | Intermediate and Long Duration Government Credit [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 496 | 420 |
| Net Asset Value [Member] | Cash and Cash Equivalent Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 114 | 118 |
| Net Asset Value [Member] | Other Investments [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 272 | 310 |
| Net Asset Value [Member] | Real Estate Funds [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | 253 | 282 |
| Net Asset Value [Member] | Other Investments, Other [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Fair value of pension and other postretirement plans' assets | $ 19 | $ 28 |
Pension and Other Postretirement Benefits - Schedule of Fair Value of Pension Plan Assets (Parenthetical) (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Retirement Benefits [Abstract] | ||
| Net receivables which represents assets related to divested businesses to be transferred to the buyers | $ 13 | $ 8 |
Pension and Other Postretirement Benefits - Schedule of Benefit Payments Expected to be Paid (Detail) $ in Millions |
Dec. 31, 2023
USD ($)
|
|---|---|
| Pension Benefits [Member] | |
| Defined Benefit Plan Disclosure [Line Items] | |
| 2024 | $ 180 |
| 2025 | 175 |
| 2026 | 175 |
| 2027 | 180 |
| 2028 | 175 |
| 2029 through 2033 | 855 |
| Total benefit payments | 1,740 |
| Other Postretirement Benefits [Member] | |
| Defined Benefit Plan Disclosure [Line Items] | |
| 2024 | 50 |
| 2025 | 50 |
| 2026 | 45 |
| 2027 | 45 |
| 2028 | 45 |
| 2029 through 2033 | 195 |
| Total benefit payments | $ 430 |
Derivatives and Other Financial Instruments - Additional Information (Detail) kt in Thousands, $ in Millions |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2023
USD ($)
Member
Smelter
kt
|
Dec. 31, 2022
USD ($)
kt
|
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Minimum members required for strategic risk management committee | Member | 3 | |
| Realized loss reclassed from Other comprehensive (loss) income to earnings | $ (130) | $ (316) |
| Unrealized gain (loss) in accumulated other comprehensive loss | $ (3,645) | (3,539) |
| Other derivative contracts estimated term of quoted market prices, in years | 10 years | |
| Other derivative beyond market estimated quoted price of aluminum by extrapolating | 10 years | |
| Level 1 [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Unrealized gain (loss) in accumulated other comprehensive loss | $ 11 | 20 |
| Level 3 [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Number of smelters | Smelter | 7 | |
| Level 1 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Realized loss reclassed from Other comprehensive (loss) income to earnings | $ 86 | 35 |
| Commodity Contract | Level 1 [Member] | Brazil [Member] | Minimum [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instrument, start date | Apr. 30, 2022 | |
| Commodity Contract | Level 1 [Member] | Brazil [Member] | Maximum [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instruments, expiration month and year | 2023-12 | |
| Commodity Contract | Level 1 [Member] | Spain [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instruments, expiration month and year | 2022-10 | |
| Foreign Exchange Forward | Brazil [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instruments, expiration month and year | 2025-08 | |
| Foreign Exchange Forward | Norway [Member] | Euro Power Purchases [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instruments, expiration month and year | 2026-12 | |
| Foreign Exchange Forward | Norway [Member] | Krone Capital Expenditures [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instruments, expiration month and year | 2025-06 | |
| Foreign Exchange Forward | Canada [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative instruments, expiration month and year | 2025-03 | |
| Sales [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Realized loss reclassed from Other comprehensive (loss) income to earnings | $ (31) | (10) |
| Cost of Goods Sold [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Realized loss reclassed from Other comprehensive (loss) income to earnings | (5) | (5) |
| Derivatives Designated as Hedging Instruments [Member] | Level 1 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Realized loss reclassed from Other comprehensive (loss) income to earnings | $ 86 | $ 35 |
| Derivatives Designated as Hedging Instruments [Member] | Power Contract [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Aluminum forecast sales | kt | 1,456 | 1,683 |
| Derivatives Designated as Hedging Instruments [Member] | Power Contract [Member] | Cash Flow Hedging [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Amount of gain (loss) expected to be recognized into earnings over the next 12 months | $ 210 | |
| Derivatives Designated as Hedging Instruments [Member] | Sales [Member] | Level 1 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Realized loss reclassed from Other comprehensive (loss) income to earnings | 91 | $ 40 |
| Derivatives Designated as Hedging Instruments [Member] | Cost of Goods Sold [Member] | Level 1 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Realized loss reclassed from Other comprehensive (loss) income to earnings | $ (5) | $ (5) |
| Derivatives Not Designated as Hedging Instruments [Member] | Financial Contracts [Member] | Level 3 [Member] | LME Price and Power Price [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Contract Termination | Jun. 30, 2026 | |
Derivatives and Other Financial Instruments - Schedule of Detail for Level 1 and 3 Derivatives (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative Assets Current | $ 29 | $ 134 |
| Derivative Liabilities Current | 214 | 200 |
| Derivative Assets Noncurrent | 3 | 2 |
| Derivative Liabilities Noncurrent | 1,092 | 1,026 |
| Unrealized gain (loss) recognized in Other comprehensive loss | (295) | (119) |
| Realized gain (loss) reclassed from Other comprehensive loss to earnings | (130) | (316) |
| Level 1 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative Assets | 16 | 84 |
| Derivative Liabilities | 9 | 14 |
| Unrealized gain (loss) recognized in Other comprehensive loss | 31 | 116 |
| Realized gain (loss) reclassed from Other comprehensive loss to earnings | 86 | 35 |
| Level 3 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative Assets | 16 | 52 |
| Derivative Liabilities | 1,297 | 1,212 |
| Unrealized gain (loss) recognized in Other comprehensive loss | (326) | (247) |
| Realized gain (loss) reclassed from Other comprehensive loss to earnings | (221) | (345) |
| Level 1 and 3 Derivative Instruments [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Derivative Assets | 32 | 136 |
| Derivative Liabilities | 1,306 | 1,226 |
| Derivative Assets Current | 29 | 134 |
| Derivative Liabilities Current | 214 | 200 |
| Derivative Assets Noncurrent | 3 | 2 |
| Derivative Liabilities Noncurrent | 1,092 | 1,026 |
| Level 2 Derivative Instruments [Member] | Non-controlling and Equity Interest [Member] | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Unrealized gain (loss) recognized in Other comprehensive loss | 12 | |
| Realized gain (loss) reclassed from Other comprehensive loss to earnings | $ 5 | $ (6) |
Derivatives and Other Financial Instruments - Schedule of Outstanding Quantities of Derivative Instruments (Detail) - Level 1 [Member] kt in Thousands, € in Millions, kr in Millions, R$ in Millions, $ in Millions |
Dec. 31, 2023
EUR (€)
kt
|
Dec. 31, 2023
NOK (kr)
kt
|
Dec. 31, 2023
BRL (R$)
kt
|
Dec. 31, 2023
CAD ($)
kt
|
Dec. 31, 2022
EUR (€)
kt
|
Dec. 31, 2022
NOK (kr)
kt
|
Dec. 31, 2022
BRL (R$)
kt
|
|---|---|---|---|---|---|---|---|
| Commodity Buy Forwards [Member] | |||||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | |||||||
| Outstanding quantities of derivative instruments | 78 | 78 | 78 | 78 | 176 | 176 | 176 |
| Commodity Sell Forwards [Member] | |||||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | |||||||
| Outstanding quantities of derivative instruments | 46 | 46 | 46 | 46 | 337 | 337 | 337 |
| Foreign Exchange Buy Forwards [Member] | |||||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | |||||||
| Derivative Liabilities | € 48 | kr 138 | R$ 467 | $ 31 | € 60 | kr 302 | R$ 1,008 |
| Foreign Exchange Sell Forwards [Member] | |||||||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | |||||||
| Derivative Liabilities | € 9 | R$ 7 |
Derivatives and Other Financial Instruments - Schedule of Fair Values of Level 3 Derivative Instruments Outstanding (Detail) - Level 3 [Member] |
12 Months Ended |
|---|---|
Dec. 31, 2023 | |
| Energy Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedging [Member] | Forward Sales One [Member] | LME Plus Midwest Premium [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Description | Embedded derivative that indexes the price of power to the LME price of aluminum plus the Midwest premium |
| Contract Termination | Mar. 31, 2026 |
| Sensitivity to Inputs | Increase in LME price and/or the Midwest premium results in a higher cost of power and an increase to the derivative liability |
| Energy Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedging [Member] | Forward Sales Two [Member] | LME Plus Midwest Premium [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Description | Embedded derivative that indexes the price of power to the LME price of aluminum plus the Midwest premium |
| Contract Termination | Dec. 31, 2029 |
| Sensitivity to Inputs | Increase in LME price and/or the Midwest premium results in a higher cost of power and an increase to the derivative liability |
| Energy Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedging [Member] | Forward Sales Three [Member] | LME Plus Midwest Premium [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Description | Embedded derivative that indexes the price of power to the LME price of aluminum plus the Midwest premium |
| Contract Termination | Feb. 29, 2036 |
| Sensitivity to Inputs | Increase in LME price and/or the Midwest premium results in a higher cost of power and an increase to the derivative liability |
| Energy Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedging [Member] | Forward Sales Four [Member] | London Metal Exchange [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Description | Embedded derivative that indexes the price of power to the LME price of aluminum |
| Contract Termination | Sep. 30, 2027 |
| Sensitivity to Inputs | Increase in LME price results in a higher cost of power and an increase to the derivative liability |
| Energy Contracts [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Estimated Credit Spread [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Description | Embedded derivative that indexes the price of power to the credit spread between the Company and the counterparty |
| Contract Termination | Oct. 31, 2028 |
| Sensitivity to Inputs | Wider credit spread results in a higher cost of power and increase in the derivative liability |
| Financial Contracts [Member] | Derivatives Not Designated as Hedging Instruments [Member] | LME Price and Power Price [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Description | Hedge power prices |
| Contract Termination | Jun. 30, 2026 |
| Sensitivity to Inputs | Lower prices in the power market or higher LME prices result in an increase in the derivative liability |
Derivatives and Other Financial Instruments - Schedule of Quantitative Information for Level 3 Derivative Contracts (Detail) - Energy Contracts [Member] - Level 3 [Member] MWh in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2023
USD ($)
MWh
$ / lb
$ / MW
| |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative assets, fair value | $ 16,000,000 |
| Derivative liabilities, fair value | 1,297,000,000 |
| Financial Contracts [Member] | Interrelationship Of Forward Energy Price, LME Forward Price And Consumer Price Index [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative assets, fair value | $ 16,000,000 |
| Financial Contracts [Member] | Interrelationship Of Forward Energy Price, LME Forward Price And Consumer Price Index [Member] | Minimum [Member] | 2024 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative forward energy price | $ / MW | 50.99 |
| LME forward price | $ 2,352 |
| Financial Contracts [Member] | Interrelationship Of Forward Energy Price, LME Forward Price And Consumer Price Index [Member] | Maximum [Member] | 2024 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative forward energy price | $ / MW | 53.55 |
| LME forward price | $ 2,424 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 2 Million MWh Per Year [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative assets, fair value | $ 0 |
| Derivative forward energy volume | MWh | 2 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 2 Million MWh Per Year [Member] | Minimum [Member] | 2024 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | $ 2,352 |
| Midwest aluminum premium | $ / lb | 0.188 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 2 Million MWh Per Year [Member] | Maximum [Member] | 2024 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | $ 2,381 |
| Midwest aluminum premium | $ / lb | 0.214 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 4 Million MWh Per Year [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative liabilities, fair value | $ 197,000,000 |
| Derivative forward energy volume | MWh | 4 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 4 Million MWh Per Year [Member] | 2024 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | $ 2,352 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 4 Million MWh Per Year [Member] | 2027 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | 2,796 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 18 Million MWh Per Year [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative liabilities, fair value | $ 1,100,000,000 |
| Derivative forward energy volume | MWh | 18 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 18 Million MWh Per Year [Member] | 2024 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | $ 2,352 |
| Midwest aluminum premium | $ / lb | 0.188 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 18 Million MWh Per Year [Member] | 2029 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | $ 2,904 |
| Midwest aluminum premium | $ / lb | 0.23 |
| Power Contract [Member] | MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 18 Million MWh Per Year [Member] | 2036 [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| LME forward price | $ 3,153 |
| Midwest aluminum premium | $ / lb | 0.23 |
| Power Contract [Member] | Estimated Spread Between The Respective 30-Year Debt Yield Of Alcoa Corporation And The Counterparty [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Derivative liabilities, fair value | $ 0 |
| Percentage of debt yield credit spread | 1.15% |
| Power Contract [Member] | Estimated Spread Between The Respective 30-Year Debt Yield Of Alcoa Corporation And The Counterparty [Member] | Counterparty [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Percentage of debt yield credit spread | 5.18% |
| Power Contract [Member] | Estimated Spread Between The Respective 30-Year Debt Yield Of Alcoa Corporation And The Counterparty [Member] | Alcoa Corporation [Member] | |
| Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
| Percentage of debt yield credit spread | 6.33% |
Derivatives and Other Financial Instruments - Schedule of Fair Values of Level 3 Derivative Instruments Recorded as Assets and Liabilities (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Assets Current | $ 29 | $ 134 |
| Derivative Liabilities Current | 214 | 200 |
| Derivative Liabilities Noncurrent | 1,092 | 1,026 |
| Level 3 [Member] | Energy Contracts [Member] | ||
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Assets | 16 | 52 |
| Liabilities | 1,297 | 1,212 |
| Level 3 [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Energy Contracts [Member] | ||
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Assets | 16 | 32 |
| Level 3 [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Financial Contracts [Member] | Energy Contracts [Member] | ||
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Assets Current | 16 | 32 |
| Level 3 [Member] | Derivatives Designated as Hedging Instruments [Member] | Energy Contracts [Member] | ||
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Assets | 0 | 20 |
| Liabilities | 1,297 | 1,212 |
| Level 3 [Member] | Derivatives Designated as Hedging Instruments [Member] | Financial Contracts [Member] | Energy Contracts [Member] | ||
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Assets Current | 0 | 20 |
| Level 3 [Member] | Derivatives Designated as Hedging Instruments [Member] | Power Contract [Member] | Energy Contracts [Member] | ||
| Derivative Instruments Gain Loss [Line Items] | ||
| Derivative Liabilities Current | 210 | 195 |
| Derivative Liabilities Noncurrent | $ 1,087 | $ 1,017 |
Derivatives and Other Financial Instruments - 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 (Detail) $ in Millions |
Dec. 31, 2023
USD ($)
|
|---|---|
| Power Contract [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Fair value asset (liability) | $ (1,297) |
| Index change of + / -10% | 300 |
| Embedded Credit Derivative [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Fair value asset (liability) | 0 |
| Index change of + / -10% | 0 |
| Financial Contracts [Member] | |
| Derivative Instruments Gain Loss [Line Items] | |
| Fair value asset (liability) | 16 |
| Index change of + / -10% | $ 8 |
Derivatives and Other Financial Instruments - Schedule of Reconciliation of Activity for Derivative Contracts (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Financial Contracts [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets, Beginning balance | $ 52 | $ 2 |
| Other comprehensive (income) loss (unrealized) | 0 | 20 |
| Settlements and other | (11) | (141) |
| Fair value measurement, Assets, Ending balance | 16 | 52 |
| Financial Contracts [Member] | Sales [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | 0 | 0 |
| Financial Contracts [Member] | Cost of Goods Sold [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | (20) | |
| Financial Contracts [Member] | Other Income Net [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | (5) | 171 |
| Financial Contracts [Member] | Other Income Net [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | (5) | 171 |
| Power Contract [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets, Beginning balance | 0 | |
| Other comprehensive (income) loss (unrealized) | 4 | |
| Settlements and other | 0 | |
| Fair value measurement, Assets, Ending balance | 0 | 0 |
| Fair value measurement, Liabilities, Beginning balance | 1,212 | 1,290 |
| Fair value measurement, Liabilities | $ (245) | $ 0 |
| Revenue from Contract with Customer, Product and Service [Extensible Enumeration] | Sales (E) | |
| Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Other (expenses) income, net (U) | |
| Other comprehensive (income) loss (unrealized) | $ 330 | $ 267 |
| Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] | Net change in unrecognized gains/losses on cash flow hedges | |
| Fair value measurement, Liabilities, Ending balance | $ 1,297 | 1,212 |
| Power Contract [Member] | Sales [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | (4) | |
| Fair value measurement, Liabilities | (345) | |
| Power Contract [Member] | Cost of Goods Sold [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | 0 | |
| Power Contract [Member] | Other Income Net [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | 0 | |
| Fair value measurement, Liabilities | 0 | |
| Power Contract [Member] | Other Income Net [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Assets | 0 | |
| Embedded Credit Derivative [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Liabilities, Beginning balance | $ 0 | 3 |
| Fair value measurement, Liabilities | $ (3) | |
| Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Other (expenses) income, net (U) | |
| Other comprehensive (income) loss (unrealized) | $ 0 | |
| Fair value measurement, Liabilities, Ending balance | 0 | |
| Embedded Credit Derivative [Member] | Sales [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Liabilities | 0 | |
| Embedded Credit Derivative [Member] | Other Income Net [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Fair value measurement, Liabilities | $ (3) | |
Derivatives and Other Financial Instruments - Schedule of Carrying Values and Fair Values of Other Financial Instruments (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Derivative [Line Items] | ||
| Short-term borrowings | $ 56 | $ 0 |
| Carrying Value [Member] | ||
| Derivative [Line Items] | ||
| Cash and cash equivalents | 944 | 1,363 |
| Restricted cash | 103 | 111 |
| Short-term borrowings | 56 | 0 |
| Long-term debt due within one year | 79 | 1 |
| Long-term debt, less amount due within one year | 1,732 | 1,806 |
| Fair Value [Member] | ||
| Derivative [Line Items] | ||
| Cash and cash equivalents | 944 | 1,363 |
| Restricted cash | 103 | 111 |
| Short-term borrowings | 56 | 0 |
| Long-term debt due within one year | 79 | 1 |
| Long-term debt, less amount due within one year | $ 1,702 | $ 1,744 |
Income Taxes - Components of (Loss) Income from Continuing Operations Before Income Taxes (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Income Tax Disclosure [Abstract] | |||
| Domestic | $ (277) | $ (652) | $ (663) |
| Foreign | (307) | 1,354 | 1,862 |
| (Loss) income before income taxes | $ (584) | $ 702 | $ 1,199 |
Income Taxes - Schedule of Provision for Income Taxes on Income from Continuing Operations (Detail) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Current: | ||||
| Federal | $ 0 | $ 0 | $ 8 | |
| Foreign | 211 | 445 | 473 | |
| State and local | 0 | 0 | 1 | |
| Current provision for income taxes, total | 211 | 445 | 482 | |
| Deferred: | ||||
| Federal | 0 | (3) | 6 | |
| Foreign | (22) | 222 | 141 | |
| Deferred provision for income taxes, total | (22) | 219 | 147 | |
| Provision for income taxes | $ (36) | $ 189 | $ 664 | $ 629 |
Income Taxes - Reconciliation of U.S. Federal Statutory Rate to Alcoa's Effective Tax Rate (Detail) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Income Tax Disclosure [Abstract] | |||
| U.S. federal statutory rate | 21.00% | 21.00% | 21.00% |
| Taxes on foreign operations—rate differential | 7.10% | 9.90% | 10.80% |
| Tax credits | 1.40% | (0.20%) | 0.00% |
| Adjustment of prior year income taxes | 0.30% | 0.00% | 0.00% |
| Noncontrolling interest | 0.20% | 0.80% | 0.50% |
| Internal legal entity reorganizations | 0.20% | (9.00%) | 0.00% |
| Tax holidays | 0.10% | (5.20%) | (2.80%) |
| Impacts of the U.S. Tax Cuts and Jobs Act of 2017 | 0.00% | 0.00% | 2.00% |
| Uncertain tax positions | (0.10%) | 0.40% | 0.00% |
| Equity loss | (5.30%) | (2.00%) | (2.50%) |
| Tax on foreign operations—other | (6.10%) | 1.30% | 1.70% |
| Changes in valuation allowances | (50.80%) | 76.70% | 23.40% |
| Other | (0.40%) | 0.90% | (1.60%) |
| Effective tax rate | (32.40%) | 94.60% | 52.50% |
Income Taxes - Additional Information (Detail) $ in Millions, $ in Millions |
1 Months Ended | 3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Aug. 16, 2022 |
Dec. 31, 2022
USD ($)
LegalEntity
|
Oct. 30, 2022
USD ($)
|
Dec. 31, 2023
USD ($)
|
Sep. 30, 2020
USD ($)
|
Sep. 30, 2020
AUD ($)
|
Dec. 31, 2023
USD ($)
Filer
|
Dec. 31, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2023
AUD ($)
|
Dec. 31, 2022
AUD ($)
|
Dec. 31, 2020
USD ($)
|
|
| Income Taxes [Line Items] | ||||||||||||
| Corporate income tax rate | 21.00% | 21.00% | 21.00% | |||||||||
| Tax expense (benefit) | $ (36) | $ 189 | $ 664 | $ 629 | ||||||||
| Deferred income taxes (Q) | (22) | 219 | 147 | |||||||||
| Deferred income taxes | 147 | 147 | ||||||||||
| Deferred tax liability | 498 | 498 | ||||||||||
| Net deferred tax assets | $ 2,958 | 3,240 | 3,240 | 2,958 | ||||||||
| Deferred tax assets, valuation allowance | 2,333 | 2,595 | 2,595 | 2,333 | $ 2,062 | $ 2,127 | ||||||
| Foreign undistributed net earnings for which no deferred taxes have been provided | 2,676 | 2,676 | ||||||||||
| Noncurrent income taxes (Q) | 215 | 193 | $ 193 | $ 215 | ||||||||
| Percentage of the effect of unrecognized tax benefit, if recorded | 1.00% | 1.00% | 0.00% | |||||||||
| Reductions for tax positions of prior years | $ 0 | $ 0 | $ 0 | |||||||||
| Interest and penalties recognized | 1 | 1 | 0 | |||||||||
| Interest income on income tax related payments | 1 | 1 | 0 | |||||||||
| Amount accrued for payment of interest and penalties | 3 | 4 | 4 | $ 3 | ||||||||
| Minimum tax on book income of corporation | 15.00% | |||||||||||
| Excise tax on net stock repurchases | 1.00% | |||||||||||
| Excise tax for common stock repurchases | 1.00% | |||||||||||
| Reversal of valuation allowance | 58 | $ 58 | ||||||||||
| Remaining cumulative income position period | 3 years | |||||||||||
| Norway [Member] | Internal Reorganization [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes (Q) | $ 30 | |||||||||||
| AWAB [Member] | Alumar Refinery [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Corporate income tax rate | 15.25% | 34.00% | ||||||||||
| Increase (decrease) in discrete income tax charge and benefit due tax holiday | $ (33) | |||||||||||
| Income tax holiday, description | The holiday related to production at the Alumar refinery was originally expected to end on December 31, 2027. During 2023, it was extended to December 31, 2032. The holiday related to the operation of the Juruti (Brazil) bauxite mine will end on December 31, 2026. | |||||||||||
| ASRI [Member] | Netherlands [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Tax expense (benefit) | $ (94) | |||||||||||
| ASRI [Member] | Norway [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Number of legal entities | LegalEntity | 4 | |||||||||||
| Number of legal entities reduced | LegalEntity | 1 | |||||||||||
| Foreign [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 147 | $ 147 | ||||||||||
| Percentage of net deferred tax asset relates to seven of Alcoa Corporation's income tax filers | 90.00% | |||||||||||
| Number of Alcoa Corporation's income tax filers | Filer | 6 | |||||||||||
| Deferred tax liability | 436 | $ 436 | ||||||||||
| Net deferred tax assets | 2,190 | 2,190 | ||||||||||
| Deferred tax assets, valuation allowance | 1,607 | $ 1,607 | ||||||||||
| Foreign [Member] | Latest Tax Year [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Income Tax Examination Year Under Examination | 2022 | |||||||||||
| Foreign [Member] | Earliest Tax Year [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Income Tax Examination Year Under Examination | 2014 | |||||||||||
| Foreign [Member] | Australian Taxation Office [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Assessed income tax amount exclusive of interest and penalties paid | $ 74 | $ 107 | ||||||||||
| Noncurrent income taxes (Q) | $ 174 | 199 | $ 199 | 174 | $ 293 | $ 260 | ||||||
| Foreign [Member] | AofA [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 185 | 185 | ||||||||||
| Foreign [Member] | AWAB [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred tax assets, valuation allowance | 106 | 154 | 154 | 106 | ||||||||
| Foreign [Member] | Alcoa Canada Company [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 135 | 135 | ||||||||||
| Foreign [Member] | Alcoa Lauralco Management Company [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 90 | 90 | ||||||||||
| Foreign [Member] | Alcoa Wolinbec Company [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 39 | 39 | ||||||||||
| Foreign [Member] | Alcoa Islandi [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 19 | 19 | ||||||||||
| Foreign [Member] | Espanola [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred tax assets, valuation allowance | $ 217 | $ 217 | 150 | |||||||||
| Foreign [Member] | Espanola [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred tax assets, valuation allowance | $ 103 | |||||||||||
| Foreign [Member] | Fjaroaal [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 35 | 35 | ||||||||||
| United States [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Deferred income taxes | 0 | 0 | ||||||||||
| Deferred tax liability | 62 | 62 | ||||||||||
| Net deferred tax assets | 1,050 | 1,050 | ||||||||||
| Deferred tax assets, valuation allowance | $ 988 | $ 988 | ||||||||||
| United States [Member] | Latest Tax Year [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Income Tax Examination Year Under Examination | 2018 | |||||||||||
| United States [Member] | Earliest Tax Year [Member] | ||||||||||||
| Income Taxes [Line Items] | ||||||||||||
| Income Tax Examination Year Under Examination | 2014 | |||||||||||
Income Taxes - Schedule of Components of Net Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|---|---|
| Income Tax Disclosure [Abstract] | ||||
| Deferred tax assets, Tax loss carryforwards | $ 2,042 | $ 1,781 | ||
| Deferred tax assets, Employee benefits | 312 | 297 | ||
| Deferred tax assets, Derivatives and hedging activities | 312 | 283 | ||
| Deferred tax assets, Loss provisions | 161 | 174 | ||
| Deferred tax assets, Depreciation | 94 | 128 | ||
| Deferred tax assets, Interest | 142 | 127 | ||
| Deferred tax assets, Investment basis differences | 78 | 75 | ||
| Deferred tax assets, Lease assets | 34 | 24 | ||
| Deferred tax assets, Tax credit carryforwards | 24 | 23 | ||
| Deferred tax assets, Deferred income/expense | 16 | 10 | ||
| Deferred tax assets, Other | 25 | 36 | ||
| Deferred tax assets, Gross | 3,240 | 2,958 | ||
| Deferred tax assets, Valuation allowance | (2,595) | (2,333) | $ (2,062) | $ (2,127) |
| Total | 645 | 625 | ||
| Deferred tax liabilities, Tax loss carryforwards | 0 | 0 | ||
| Deferred tax liabilities, Employee benefits | 0 | 0 | ||
| Deferred tax liabilities, Derivatives and hedging activities | 10 | 24 | ||
| Deferred tax liabilities, Loss provisions | 0 | 0 | ||
| Deferred tax liabilities, Depreciation | 318 | 336 | ||
| Deferred tax liabilities, Interest | 6 | 2 | ||
| Deferred tax liabilities, Investment basis differences | 0 | 0 | ||
| Deferred tax liabilities, Lease liabilities | 33 | 23 | ||
| Deferred tax liabilities, Tax credit carryforwards | 0 | 0 | ||
| Deferred tax liabilities, Deferred income/expense | 131 | 153 | ||
| Deferred tax liabilities, Other | 0 | 0 | ||
| Deferred tax liabilities, Gross | 498 | 538 | ||
| Deferred tax liabilities, Valuation allowance | 0 | 0 | ||
| Total | $ 498 | $ 538 |
Income Taxes - Schedule of Expiration Periods of Deferred Tax Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|---|---|
| Tax Credit Carryforward [Line Items] | ||||
| Tax loss carryforwards | $ 2,042 | |||
| Tax credit carryforwards | 24 | $ 23 | ||
| Other | 1,174 | |||
| Valuation allowance | (2,595) | (2,333) | $ (2,062) | $ (2,127) |
| Total | 645 | $ 625 | ||
| Expires Within 10 Years [Member] | ||||
| Tax Credit Carryforward [Line Items] | ||||
| Tax loss carryforwards | 203 | |||
| Tax credit carryforwards | 24 | |||
| Other | (1) | |||
| Valuation allowance | (226) | |||
| Total | 0 | |||
| Expires Within 11-20 Years [Member] | ||||
| Tax Credit Carryforward [Line Items] | ||||
| Tax loss carryforwards | 333 | |||
| Valuation allowance | (333) | |||
| Total | 0 | |||
| No Expiration [Member] | ||||
| Tax Credit Carryforward [Line Items] | ||||
| Tax loss carryforwards | 1,471 | |||
| Other | 154 | |||
| Valuation allowance | (1,613) | |||
| Total | 12 | |||
| Other [Member] | ||||
| Tax Credit Carryforward [Line Items] | ||||
| Tax loss carryforwards | 35 | |||
| Other | 1,021 | |||
| Valuation allowance | (423) | |||
| Total | $ 633 |
Income Taxes - Composition of Net Deferred Tax Asset by Jurisdiction (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|---|---|
| Income Tax Disclosure [Line Items] | ||||
| Deferred tax assets | $ 3,240 | $ 2,958 | ||
| Valuation allowance | (2,595) | $ (2,333) | $ (2,062) | $ (2,127) |
| Deferred tax liabilities | (498) | |||
| Total | 147 | |||
| Domestic [Member] | ||||
| Income Tax Disclosure [Line Items] | ||||
| Deferred tax assets | 1,050 | |||
| Valuation allowance | (988) | |||
| Deferred tax liabilities | (62) | |||
| Total | 0 | |||
| Foreign [Member] | ||||
| Income Tax Disclosure [Line Items] | ||||
| Deferred tax assets | 2,190 | |||
| Valuation allowance | (1,607) | |||
| Deferred tax liabilities | (436) | |||
| Total | $ 147 |
Income Taxes - Schedule of Changes in Valuation Allowance (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Income Tax Disclosure [Abstract] | |||
| Balance at beginning of year | $ (2,333) | $ (2,062) | $ (2,127) |
| Establishment of new allowances | (106) | (150) | (103) |
| Net change to existing allowances | (113) | (151) | 139 |
| Foreign currency translation | (43) | 30 | 29 |
| Balance at end of year | $ (2,595) | $ (2,333) | $ (2,062) |
Income Taxes - Reconciliation of Unrecognized Tax Benefits (Excluding Interest and Penalties) (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Income Tax Disclosure [Abstract] | |||
| Balance at beginning of year | $ 5 | $ 4 | $ 4 |
| Additions for tax positions of prior years | 0 | 2 | 0 |
| Reductions for tax positions of prior years | 0 | 0 | 0 |
| Expiration of the statute of limitations | 0 | (1) | 0 |
| Foreign currency translation | 0 | 0 | 0 |
| Balance at end of year | $ 5 | $ 5 | $ 4 |
Asset Retirement Obligations - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Asset Retirement Obligations [Line Items] | ||
| Current liability | $ 217 | $ 117 |
| Liabilities incurred | 254 | 224 |
| Reversals of previously recorded liabilities | (8) | (12) |
| Restructuring and Other Charges [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 34 | |
| Cost of Goods Sold [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 15 | 72 |
| Magnesium Smelter Facility in Addy [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 15 | |
| Bauxite Residue Areas [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 97 | 81 |
| Mine Areas [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 87 | 79 |
| Intalco Smelter [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 36 | |
| Intalco Smelter [Member] | Restructuring and Other Charges [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 41 | |
| Spent Pot Lining Treatment and Disposal [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 23 | 28 |
| Non-Operating Bauxite Residue Areas [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 10 | |
| Bauxite Residue Areas Related to Water Management [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 18 | |
| Demolition Projects [Member] | ||
| Asset Retirement Obligations [Line Items] | ||
| Liabilities incurred | 1 | 3 |
| Reversals of previously recorded liabilities | $ 8 | $ 12 |
Asset Retirement Obligations - Schedule of Carrying Value of Recorded AROs by Major Category (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|---|---|---|---|
| Asset Retirement Obligation Disclosure [Abstract] | |||
| Closure of bauxite residue areas | $ 437 | $ 342 | |
| Mine reclamation | 328 | 279 | |
| Spent pot lining disposal | 124 | 115 | |
| Demolition | 76 | 61 | |
| Landfill closure | 24 | 31 | |
| Balance at end of year | $ 989 | $ 828 | $ 738 |
Asset Retirement Obligations - Schedule of Changes in Carrying Value of Recorded AROs (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Asset Retirement Obligation Disclosure [Abstract] | ||
| Balance at beginning of year | $ 828 | $ 738 |
| Accretion expense | 33 | 20 |
| Liabilities incurred | 254 | 224 |
| Payments | (148) | (114) |
| Reversals of previously recorded liabilities | (8) | (12) |
| Foreign currency translation and other | 30 | (28) |
| Balance at end of year | $ 989 | $ 828 |
Asset Retirement Obligations - Schedule of Estimated Timing of Cash Outflows on Asset Retirement Obligations (Details) $ in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2023
USD ($)
| |
| Asset Retirement Obligation Disclosure [Abstract] | |
| 2024 | $ 217 |
| 2025 - 2028 | 573 |
| Thereafter | 199 |
| Total | $ 989 |
Contingencies and Commitments - Changes in Carrying Value of Recorded Environmental Remediation Reserves (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Commitments and Contingencies Disclosure [Abstract] | |||
| Beginning balance | $ 284 | $ 309 | $ 322 |
| Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] | Environmental remediation (S) | ||
| Liabilities incurred | 39 | 32 | $ 21 |
| Cash payments | (55) | (26) | (23) |
| Reversals of previously recorded liabilities | (1) | (30) | (17) |
| Foreign currency translation and other | 1 | (1) | 6 |
| Ending balance | $ 268 | $ 284 | $ 309 |
Contingencies and Commitments - Additional Information (Detail) $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 31, 2023
USD ($)
Project
|
Dec. 31, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2020
USD ($)
|
|
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | $ 39 | $ 32 | $ 21 | |
| Payments against the reserve | 55 | 26 | 23 | |
| Reversals of previously recorded liabilities | 1 | 30 | 17 | |
| Environmental remediation reserve balance, current | $ 66 | $ 58 | ||
| Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] | Other current liabilities | Other current liabilities | ||
| Active or future remediation for significant sites | $ 211 | $ 234 | ||
| Accrued environmental reserves | 268 | 284 | 309 | $ 322 |
| Former East St. Louis Site [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | 4 | |||
| Magnesium Smelter Facility in Addy [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | 14 | |||
| Point Henry Site [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | 6 | |||
| Environmental activiteis | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | 9 | |||
| Intalco Aluminum Smelter [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | $ 14 | |||
| Massena East Site [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Reversals of previously recorded liabilities | 18 | |||
| Suralco [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Reversals of previously recorded liabilities | 5 | |||
| Closed Site in Brazil [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Reversals of previously recorded liabilities | 6 | 5 | ||
| Closed Suriname Site [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Reversals of previously recorded liabilities | 7 | |||
| Closed Tennessee Site [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Reversals of previously recorded liabilities | $ 5 | |||
| Massena, New York [Member] | Minimum [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Environmental remediation work completion period | 4 years | |||
| Massena, New York [Member] | Maximum [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Environmental remediation work completion period | 8 years | |||
| Longview, Washington [Member] | Ongoing Remediation Work [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | $ 13 | |||
| Addy, Washington [Member] | Minimum [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Environmental remediation work completion period | 3 years | |||
| Addy, Washington [Member] | Maximum [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Environmental remediation work completion period | 5 years | |||
| Ferndale Washington [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Post-closure maintenance and monitoring period | 5 years | |||
| Other Sites [Member] | ||||
| Loss Contingencies [Line Items] | ||||
| Liabilities incurred | $ 12 | |||
| Number of remediation projects | Project | 32 | |||
| Accrued environmental reserves | $ 57 | $ 50 | ||
Contingencies and Commitments - Estimate Timing of Cash Outflows from Environmental Reserves (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|---|---|
| Commitments and Contingencies Disclosure [Abstract] | ||||
| 2024 | $ 66 | |||
| 2025 - 2028 | 112 | |||
| Thereafter | 90 | |||
| Total | $ 268 | $ 284 | $ 309 | $ 322 |
Contingencies and Commitments - Additional Information - 1 (Detail) $ in Millions |
1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended | |||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Sep. 17, 2020
USD ($)
|
Sep. 17, 2020
AUD ($)
|
Aug. 31, 2022
USD ($)
|
Aug. 31, 2022
BRL (R$)
|
Jul. 31, 2022
USD ($)
|
Jul. 31, 2022
BRL (R$)
|
Mar. 31, 2022
USD ($)
|
Mar. 31, 2022
BRL (R$)
|
Feb. 28, 2022
USD ($)
|
Feb. 28, 2022
BRL (R$)
|
Mar. 31, 2013
USD ($)
|
May 31, 2012
USD ($)
|
May 31, 2012
BRL (R$)
|
Sep. 30, 2020
USD ($)
|
Dec. 31, 2023
USD ($)
|
Dec. 31, 2023
USD ($)
|
Dec. 31, 2023
BRL (R$)
|
Dec. 31, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2023
AUD ($)
|
Dec. 31, 2022
AUD ($)
|
Jul. 31, 2022
BRL (R$)
|
Feb. 28, 2022
BRL (R$)
|
Sep. 30, 2020
AUD ($)
|
Jul. 07, 2020
USD ($)
|
Jul. 07, 2020
AUD ($)
|
Mar. 31, 2013
BRL (R$)
|
|
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Other noncurrent liabilities and deferred credits (U) | $ 568,000,000 | $ 568,000,000 | $ 486,000,000 | ||||||||||||||||||||||||
| Restructuring and other charges, net (D) | $ 184,000,000 | 696,000,000 | $ 1,128,000,000 | ||||||||||||||||||||||||
| Payment for settlements to former employees | $ 76,000,000 | ||||||||||||||||||||||||||
| AWAC [Member] | Alumina Limited [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Non-controlling interest, ownership percentage | 40.00% | 40.00% | 40.00% | ||||||||||||||||||||||||
| Australian Taxation Office [Member] | Foreign Jurisdiction [Member] | AofA [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Additional income tax payable, exclusive of interest and penalties | $ 145,000,000 | $ 214 | |||||||||||||||||||||||||
| Notices include claims for compounded interest on the tax amount | $ 481,000,000 | $ 707 | |||||||||||||||||||||||||
| Proposed administrative penalties | $ 87,000,000 | $ 128 | |||||||||||||||||||||||||
| Payment of dispute resolution practices income tax percentage | 50.00% | ||||||||||||||||||||||||||
| Assessed income tax amount exclusive of interest and penalties | $ 74,000,000 | $ 107 | |||||||||||||||||||||||||
| Payment amount refund percentage | 50.00% | ||||||||||||||||||||||||||
| Tax assessment deposit | $ 73,000,000 | $ 73,000,000 | $ 107 | ||||||||||||||||||||||||
| Other noncurrent liabilities and deferred credits (U) | $ 199,000,000 | $ 199,000,000 | 174,000,000 | $ 293 | $ 260 | ||||||||||||||||||||||
| Alcoa World Alumina Brasil [Member] | Brazilian Federal Revenue Office [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Disallowed tax credits | $ 13,000,000 | $ 4,000,000 | $ 110,000,000 | R$ 70,000,000 | R$ 19,000,000 | R$ 220,000,000 | |||||||||||||||||||||
| Percentage of penalty of the gross disallowed amount | 50.00% | ||||||||||||||||||||||||||
| Value added tax receivable | $ 6,000,000 | R$ 31,000,000 | $ 16,000,000 | R$ 84,000,000 | $ 9,000,000 | R$ 44,000,000 | $ 14,000,000 | R$ 65,000,000 | $ 41,000,000 | R$ 82,000,000 | |||||||||||||||||
| Alcoa Corporation [Member] | AWAC [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Ownership interest percentage | 60.00% | 60.00% | 60.00% | ||||||||||||||||||||||||
| Minimum [Member] | Alcoa World Alumina Brasil [Member] | Brazilian Federal Revenue Office [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Charge recorded in provision for income taxes to establish liability for estimated loss | $ 0 | ||||||||||||||||||||||||||
| Maximum [Member] | Alcoa World Alumina Brasil [Member] | Brazilian Federal Revenue Office [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Charge recorded in provision for income taxes to establish liability for estimated loss | $ 49,000,000 | R$ 239,000,000 | |||||||||||||||||||||||||
| Aviles and La Coruna Smelters [Member] | Maximum [Member] | Parter Capital Group A G | Spain [Member] | Aviles and La Coruea Aluminum Facilities [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Financial Contributions | 95,000,000 | ||||||||||||||||||||||||||
| Financial contributions paid to buyer in relation to divestiture | $ 78,000,000 | ||||||||||||||||||||||||||
| Aviles and La Coruna Facilities [Member] | |||||||||||||||||||||||||||
| Loss Contingencies [Line Items] | |||||||||||||||||||||||||||
| Restructuring and other charges, net (D) | $ 79,000,000 | ||||||||||||||||||||||||||
Contingencies and Commitments - Additional Information - 2 (Detail) $ in Millions |
1 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|
|
Apr. 08, 2015
USD ($)
Refinery
|
Apr. 30, 2016
Refinery
|
Dec. 31, 2023
USD ($)
|
Dec. 31, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2023
AUD ($)
|
Aug. 31, 2017
USD ($)
|
|
| Loss Contingencies [Line Items] | |||||||
| Number of alumina refineries to be powered under supplied agreement | Refinery | 3 | ||||||
| Total asset | $ 283,000,000 | $ 311,000,000 | |||||
| Guarantees of third party related to project financing | $ 0 | 0 | |||||
| Line of credit renew or expire starting year | 2024 | ||||||
| Line of credit renew or expire ending year | 2025 | ||||||
| Letters of credit, total amount committed | $ 294,000,000 | ||||||
| Letter of credit agreement, expiration date | Jun. 27, 2024 | ||||||
| Total amount committed under outstanding surety bonds | $ 190,000,000 | ||||||
| Minimum [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Surety bonds, expiration date | 2024 | ||||||
| Maximum [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Surety bonds, expiration date | 2028 | ||||||
| Alcoa Corporation [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Outstanding bank guarantees and letters of credit | $ 13,000,000 | ||||||
| Total amount committed under outstanding surety bonds | 8,000,000 | ||||||
| Parent Co [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Outstanding bank guarantees and letters of credit | 8,000,000 | ||||||
| Total amount committed under outstanding surety bonds | 5,000,000 | ||||||
| Standby Letter of Credit Agreement [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Line of credit facility, outstanding borrowings | 86,000,000 | ||||||
| Principal amount of debt | $ 200,000,000 | ||||||
| Letter of Credit [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Line of credit facility, outstanding borrowings | 86,000,000 | ||||||
| AofA [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Bank guarantee | 68,000,000 | $ 100 | |||||
| AofA [Member] | Service Agreements [Member] | Alcoa Corporation [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Number of alumina refineries to be powered under supplied agreement | Refinery | 3 | ||||||
| Gas supply agreement prepayment amount | $ 500,000,000 | ||||||
| AofA [Member] | Service Agreements [Member] | Prepaid Expenses and Other Current Assets [Member] | Alcoa Corporation [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Total asset | 37,000,000 | 37,000,000 | |||||
| AofA [Member] | Service Agreements [Member] | Other Noncurrent Assets [Member] | Alcoa Corporation [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Total asset | $ 283,000,000 | 311,000,000 | |||||
| Energy Obligation [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Expiration date of unconditional purchase obligations for energy starting year | 2040 | ||||||
| Expiration date of unconditional purchase obligations for energy ending year | 2041 | ||||||
| Purchase obligations due in 2024 | $ 56,000,000 | ||||||
| Purchase obligations due in 2025 | 59,000,000 | ||||||
| Purchase obligations due in 2026 | 61,000,000 | ||||||
| Purchase obligations due in 2027 | 63,000,000 | ||||||
| Purchase obligations due in 2028 | 65,000,000 | ||||||
| Purchase obligations due thereafter | 770,000,000 | ||||||
| Purchase obligations expenditures | 53,000,000 | $ 58,000,000 | $ 86,000,000 | ||||
| Energy Raw Materials And Other Goods And Services [Member] | |||||||
| Loss Contingencies [Line Items] | |||||||
| Purchase obligations due in 2024 | 3,896,000,000 | ||||||
| Purchase obligations due in 2025 | 1,998,000,000 | ||||||
| Purchase obligations due in 2026 | 1,566,000,000 | ||||||
| Purchase obligations due in 2027 | 1,448,000,000 | ||||||
| Purchase obligations due in 2028 | 1,407,000,000 | ||||||
| Purchase obligations due thereafter | $ 8,757,000,000 | ||||||
Leasing - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Leases [Line Items] | ||
| Remaining lease term | 1 year | |
| New leases | $ 76 | $ 26 |
| Maximum [Member] | ||
| Leases [Line Items] | ||
| Remaining lease term | 59 years | |
Leasing - Schedule of Lease Expense and Operating Cash Flows (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Leases [Abstract] | ||
| Costs from operating leases | $ 53 | $ 54 |
| Variable lease payments | 25 | 16 |
| Short-term rental expense | $ 11 | $ 2 |
Leasing - Schedule of Weighted Average Lease Term and Weighted Average Discount Rate (Detail) |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Leases [Abstract] | ||
| Weighted average lease term for operating leases (years) | 12 years 10 months 24 days | 5 years 1 month 6 days |
| Weighted average discount rate for operating leases | 6.70% | 5.60% |
Leasing - Schedule of Aggregate Right-of Use Assets and Related Lease Obligations (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Leases [Abstract] | ||
| Properties, plants, and equipment, net | $ 135 | $ 89 |
| Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Other noncurrent assets (U) | Other noncurrent assets (U) |
| Other current liabilities | $ 31 | $ 30 |
| Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Other current liabilities | Other current liabilities |
| Other noncurrent liabilities and deferred credits | $ 104 | $ 59 |
| Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Other noncurrent liabilities and deferred credits (U) | Other noncurrent liabilities and deferred credits (U) |
| Total operating lease liabilities | $ 135 | $ 89 |
Leasing - Schedule of Future Cash Flows Related to Operating Lease Obligations (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Leases [Abstract] | ||
| 2024 | $ 40 | |
| 2025 | 26 | |
| 2026 | 20 | |
| 2027 | 16 | |
| 2028 | 11 | |
| Thereafter | 112 | |
| Total lease payments (undiscounted) | 225 | |
| Less: discount to net present value | (90) | |
| Total | $ 135 | $ 89 |
Other Financial Information - Schedule of Interest Cost Components (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Other Financial Information [Abstract] | |||
| Amount charged to expense | $ 107 | $ 106 | $ 195 |
| Amount capitalized | 4 | 3 | 6 |
| Interest costs, total | $ 111 | $ 109 | $ 201 |
Other Financial Information - Schedule of Other Expenses (Income), Net (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Other Income and Expenses [Abstract] | |||
| Equity loss (income) | $ 228 | $ 27 | $ (105) |
| Foreign currency (gains) losses, net | (64) | 9 | 3 |
| Net loss (gain) from asset sales | 14 | 10 | (354) |
| Net loss (gain) on mark-to-market derivative instruments | 5 | (174) | (25) |
| Non-service costs - pension and other postretirement benefits | 13 | 60 | 47 |
| Other, net | (62) | (50) | (11) |
| Other expenses, net | $ 134 | $ (118) | $ (445) |
Other Financial Information - Additional Information (Detail) $ in Millions |
1 Months Ended | 3 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|---|
|
Jun. 30, 2022
USD ($)
|
Apr. 30, 2016
Refinery
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2023
USD ($)
|
Dec. 31, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2020
Subsidiary
|
|
| Other Non operating Income Expense [Line Items] | |||||||
| Interest income | $ 62 | $ 50 | |||||
| Net gain from asset sales | (18) | (10) | $ 354 | ||||
| Number of alumina refineries to be powered under supplied agreement | Refinery | 3 | ||||||
| VAT credits payable | 58 | 51 | |||||
| Sales | 10,551 | 12,451 | 12,152 | ||||
| Reversed the allowance with credit of restructuring and other charges, net | $ (83) | ||||||
| Valuation allowance with credit to cost of goods sold | $ (46) | ||||||
| Restricted cash | 91 | ||||||
| Capital improvements at the site | 118 | ||||||
| Restart Costs | 35 | ||||||
| Capital investment expenditures | 28 | ||||||
| Dampier to Bunbury Natural Gas Pipeline [Member] | AofA [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| Investment percentage | 30.00% | ||||||
| Prepayments made under the agreement for future gas transmission services | 297 | 285 | |||||
| Brazil [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| Sales | $ 735 | $ 527 | 610 | ||||
| Brazil [Member] | Alcoa World Alumina Brazil and Alcoa Aluminio [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| Number of subsidiaries | Subsidiary | 2 | ||||||
| Sales | $ 34 | ||||||
| Brazil [Member] | Alcoa World Alumina Brazil and Alcoa Aluminio [Member] | Other Noncurrent Assets [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| Additional VAT credits recorded | 95 | ||||||
| Brazil [Member] | Alcoa World Alumina Brazil and Alcoa Aluminio [Member] | Other Income Net [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| Interest income | 14 | ||||||
| Brazil [Member] | Alcoa World Alumina Brazil and Alcoa Aluminio [Member] | Other Noncurrent Liabilities [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| VAT credits payable | $ 47 | 47 | |||||
| Eastalco Site Sale And Warrick Rolling Mill [Member] | |||||||
| Other Non operating Income Expense [Line Items] | |||||||
| Net gain from asset sales | $ 354 | ||||||
Other Financial Information - Schedule of Other Noncurrent Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Other Financial Information [Abstract] | ||
| Gas supply prepayment | $ 283 | $ 311 |
| Prepaid gas transmission contract | 297 | 285 |
| Value-added tax credits | 336 | 294 |
| Deferred mining costs, net | 187 | 161 |
| Goodwill | 146 | 145 |
| Prepaid pension benefit | 125 | 146 |
| Noncurrent prepaid tax asset | 73 | 72 |
| Noncurrent restricted cash | 71 | 56 |
| Intangibles, net | 37 | 29 |
| Other | 95 | 94 |
| Other assets, noncurrent, total | $ 1,650 | $ 1,593 |
Other Financial Information - Schedule of Other Noncurrent Liabilities and Deferred Credits (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Other Financial Information [Abstract] | ||
| Noncurrent accrued tax liability | $ 199 | $ 174 |
| Operating lease obligations | 104 | 59 |
| Accrued compensation and retirement costs | 94 | 95 |
| Value added tax credits payable to Arconic Corporation | 58 | 51 |
| Deferred energy credits | 42 | 37 |
| Noncurrent restructuring reserve | 15 | 3 |
| Deferred alumina sales revenue | 20 | 28 |
| Other | 36 | 39 |
| Other noncurrent liabilities and deferred credits, total | $ 568 | $ 486 |
Other Financial Information - Schedule of Cash and Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|---|---|
| Other Financial Information [Abstract] | ||||
| Cash and cash equivalents | $ 944 | $ 1,363 | ||
| Current restricted cash | 32 | 55 | ||
| Noncurrent restricted cash | 71 | 56 | ||
| Cash and cash equivalents and restricted cash, total | $ 1,047 | $ 1,474 | $ 1,924 | $ 1,610 |
Other Financial Information - Schedule of Cash Paid for Interest and Income Taxes (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Other Financial Information [Abstract] | |||
| Interest, net of amount capitalized | $ 100 | $ 100 | $ 191 |
| Income taxes, net of amount refunded | $ 319 | $ 504 | $ 152 |
Supplier Finance Programs - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Supplier invoices outstanding | $ 104 | $ 185 |
| Minimum [Member] | ||
| Payment terms | 50 days | |
| Maximum [Member] | ||
| Payment terms | 110 days |
Subsequent Events - Additional Information (Detail) - Kwinana Refinery [Member] MT in Millions, $ in Millions |
3 Months Ended | |||
|---|---|---|---|---|
|
Jan. 08, 2024
Employee
MT
|
Mar. 31, 2024
USD ($)
|
Sep. 30, 2025
Employee
|
Sep. 30, 2024
Employee
|
|
| Scenario Forecast [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Number of employees | Employee | 50 | 250 | ||
| Cash outlays spent in 2023 | $ 115 | |||
| Cash outlays expected in 2024 | 80 | |||
| Cash outlays expected in 2025 | 35 | |||
| Scenario Forecast [Member] | Maximum [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Restructuring charges | 200 | |||
| Scenario Forecast [Member] | Minimum [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Restructuring charges | 180 | |||
| Scenario Forecast [Member] | Water Management Costs [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Restructuring charges | 81 | |||
| Scenario Forecast [Member] | Employee Related Costs [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Restructuring charges | 55 | |||
| Scenario Forecast [Member] | Asset Retirement Obligations [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Restructuring charges | 26 | |||
| Scenario Forecast [Member] | Other Costs [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Restructuring charges | $ 18 | |||
| Subsequent Event [Member] | ||||
| Subsequent Event [Line Items] | ||||
| Number of employees | Employee | 800 | |||
| Percentage of operating production of annual capacity | 80.00% | |||
| Annual capacity of production | MT | 2.2 |