Entity Central Index Key Segment reporting information unrelated party sales. Segment reporting information intersegment revenues. The total costs of sales, operating expenses, and nonoperating expenses/income. Adjusted EBITDA. Segment Reporting Information Transformation. Segment reporting information intersegment eliminations Segment reporting information corporate expenses. Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Includes expenses related to certain asset retirement obligations. Segment reporting information other income expense net. Lessee, operating lease, liability, payments due after year four. Cover [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address Address Line1 Entity Address, Address Line Two Entity Address Address Line2 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Interactive Data Current Entity Interactive Data Current Title of 12(b) Security Security12b Title Security Exchange Name Security Exchange Name Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Income Statement [Abstract] Sales (E) Revenue From Contract With Customer Excluding Assessed Tax Cost of goods sold (exclusive of expenses below) Cost Of Goods And Service Excluding Depreciation Depletion And Amortization Selling, general administrative, and other expenses Selling General And Administrative Expense Research and development expenses Research And Development Expense Provision for depreciation, depletion, and amortization Depreciation Depletion And Amortization Restructuring and other charges, net (D) Restructuring And Other Charges Interest expense Interest Expense Other income, net (P) Nonoperating Income Expense Total costs and expenses Costs And Operating Expenses And Nonoperating Income Expenses Income before income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Provision for income taxes Income Tax Expense Benefit Net income Profit Loss Less: Net income attributable to noncontrolling interest Net Income Loss Attributable To Noncontrolling Interest NET INCOME ATTRIBUTABLE TO ALCOA CORPORATION Net Income Loss EARNINGS PER SHARE ATTRIBUTABLE TO ALCOA CORPORATION COMMON SHAREHOLDERS (F): Earnings Per Share [Abstract] Basic Earnings Per Share Basic Diluted Earnings Per Share Diluted Statement of Comprehensive Income [Abstract] Statement Of Income And Comprehensive Income [Abstract] Net income, Noncontrolling interest Net income Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits, Alcoa Corporation Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits, Noncontrolling interest Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest Change in unrecognized net actuarial loss and prior service cost/benefit related to pension and other postretirement benefits Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax Foreign currency translation adjustments, Alcoa Corporation Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent Foreign currency translation adjustments, Noncontrolling interest Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest Foreign currency translation adjustments Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax Net change in unrecognized gains/losses on cash flow hedges, Alcoa Corporation Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent Net change in unrecognized gains/losses on cash flow hedges, Noncontrolling interest Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Noncontrolling Interest Net change in unrecognized gains/losses on cash flow hedges Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Total Other comprehensive (loss) income, net of tax, Alcoa Corporation Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Total Other comprehensive (loss) income, net of tax, Noncontrolling interest Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest Total Other comprehensive (loss) income, net of tax Other Comprehensive Income Loss Net Of Tax Comprehensive (loss) income, Alcoa Corporation Comprehensive Income Net Of Tax Comprehensive (loss) income, Noncontrolling interest Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest Comprehensive (loss) income Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest Statement Of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents (L) Cash And Cash Equivalents At Carrying Value Receivables from customers Accounts Receivable Net Current Other receivables Other Receivables Net Current Inventories (I) Inventory Net Fair value of derivative instruments (L) Derivative Assets Current Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Properties, plants, and equipment Property Plant And Equipment Gross Less: accumulated depreciation, depletion, and amortization Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Properties, plants, and equipment, net Property Plant And Equipment Net Investments (H) Investments In Affiliates Subsidiaries Associates And Joint Ventures Deferred income taxes Deferred Income Tax Assets Net Fair value of derivative instruments (L) Derivative Assets Noncurrent Other noncurrent assets Other Assets Noncurrent Total assets Assets LIABILITIES Liabilities [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable, trade Accounts Payable Current Accrued compensation and retirement costs Employee Related Liabilities Current Taxes, including income taxes Taxes Payable Current Fair value of derivative instruments (L) Derivative Liabilities Current Other current liabilities Other Liabilities Current Long-term debt due within one year (J & L) Long Term Debt And Capital Lease Obligations Current Total current liabilities Liabilities Current Long-term debt, less amount due within one year (J & L) Long Term Debt And Capital Lease Obligations Accrued pension benefits (K) Defined Benefit Pension Plan Liabilities Noncurrent Accrued other postretirement benefits (K) Other Postretirement Defined Benefit Plan Liabilities Noncurrent Asset retirement obligations Asset Retirement Obligations Noncurrent Environmental remediation (O) Accrued Environmental Loss Contingencies Noncurrent Fair value of derivative instruments (L) Derivative Liabilities Noncurrent Noncurrent income taxes Accrued Income Taxes Noncurrent Other noncurrent liabilities and deferred credits Deferred Credits And Other Liabilities Noncurrent Total liabilities Liabilities CONTINGENCIES AND COMMITMENTS (O) Commitments And Contingencies EQUITY Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract] Alcoa Corporation shareholders’ equity: Stockholders Equity [Abstract] Common stock Common Stock Value Additional capital Additional Paid In Capital Common Stock Retained earnings (deficit) Retained Earnings Accumulated Deficit Accumulated other comprehensive loss (G) Accumulated Other Comprehensive Income Loss Net Of Tax Total Alcoa Corporation shareholders’ equity Stockholders Equity Noncontrolling interest Minority Interest Total equity Stockholders Equity Including Portion Attributable To Noncontrolling Interest Total liabilities and equity Liabilities And Stockholders Equity The total amount of net periodic benefit cost for defined benefit pension plans for the period excluding settlements, curtailments, and special termination benefits related to restructuring actions. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. Long term debt issued less issuance discount. Payments for financial contributions for the divestiture of businesses. Statement Of Cash Flows [Abstract] CASH FROM OPERATIONS Net Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income to cash from operations: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Deferred income taxes Deferred Income Tax Expense Benefit Equity earnings, net of dividends Income Loss From Equity Method Investments Net Of Dividends Or Distributions Restructuring and other charges, net (D) Net loss (gain) from investing activities – asset sales (P) Gain Loss On Disposition Of Assets1 Net periodic pension benefit cost (K) Defined Benefit Pension Plans Net Periodic Benefit Cost Stock-based compensation Share Based Compensation Other Other Noncash Income Expense Changes in assets and liabilities, excluding effects of divestitures and foreign currency translation adjustments: Increase Decrease In Operating Capital [Abstract] (Increase) in receivables Increase Decrease In Receivables (Increase) in inventories Increase Decrease In Inventories (Increase) Decrease in prepaid expenses and other current assets Increase Decrease In Prepaid Deferred Expense And Other Assets (Decrease) in accounts payable, trade Increase Decrease In Accounts Payable Trade (Decrease) Increase in accrued expenses Increase Decrease In Accrued Liabilities (Decrease) in taxes, including income taxes Increase Decrease In Accrued Taxes Payable Pension contributions (K) Pension Contributions Decrease (Increase) in noncurrent assets Increase Decrease In Other Noncurrent Assets (Decrease) in noncurrent liabilities Increase Decrease In Other Noncurrent Liabilities CASH PROVIDED FROM OPERATIONS Net Cash Provided By Used In Operating Activities FINANCING ACTIVITIES Net Cash Provided By Used In Financing Activities [Abstract] Additions to debt (original maturities greater than three months) Additions To Long Term Debt Issued Less Issuance Discount Proceeds from the exercise of employee stock options Proceeds From Stock Options Exercised Repurchase of common stock Payments For Repurchase Of Common Stock Dividends paid on Alcoa common stock Payments Of Dividends Common Stock Payments related to tax withholding on stock-based compensation awards Payments Related To Tax Withholding For Share Based Compensation Financial contributions for the divestiture of businesses (D) Payments For Financial Contributions For The Divestiture Of Businesses Contributions from noncontrolling interest Proceeds From Minority Shareholders Distributions to noncontrolling interest Payments Of Dividends Minority Interest Other Proceeds From Payments For Other Financing Activities CASH (USED FOR) PROVIDED FROM FINANCING ACTIVITIES Net Cash Provided By Used In Financing Activities INVESTING ACTIVITIES Net Cash Provided By Used In Investing Activities [Abstract] Capital expenditures Payments To Acquire Property Plant And Equipment Proceeds from the sale of assets Proceeds From Sale Of Property Plant And Equipment Additions to investments Payments To Acquire Investments CASH (USED FOR) PROVIDED FROM INVESTING ACTIVITIES Net Cash Provided By Used In Investing Activities EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS AND RESTRICTED CASH Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Net change in cash and cash equivalents and restricted cash Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash and cash equivalents and restricted cash at beginning of year Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CASH AND CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD The minority interest increase decrease from capital contribution from noncontrolling interest holders. Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Capital [Member] Additional Paid In Capital [Member] Retained Earnings (Deficit) [Member] Retained Earnings [Member] Accumulated Other Comprehensive Loss [Member] Accumulated Other Comprehensive Income [Member] Non-controlling Interest [Member] Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Balance Stock-based compensation Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Common stock issued: compensation plans Stock Issued During Period Value Share Based Compensation Repurchase of common stock Stock Repurchased During Period Value Dividends paid on Alcoa common stock Dividends Common Stock Contributions Minority Interest Increase Decrease From Capital Contribution From Noncontrolling Interest Holders Distributions Minority Interest Decrease From Distributions To Noncontrolling Interest Holders Other Stockholders Equity Other Balance Common stock dividends per share Common Stock Dividends Per Share Cash Paid Organization Consolidation And Presentation Of Financial Statements [Abstract] Basis of Presentation Basis Of Accounting New Accounting Pronouncements And Changes In Accounting Principles [Abstract] Recently Adopted and Recently Issued Accounting Guidance New Accounting Pronouncements And Changes In Accounting Principles [Text Block] Divestitures and held for sale. Business Combinations [Abstract] Divestitures Divestitures And Held For Sale Disclosure [Text Block] Restructuring And Related Activities [Abstract] Restructuring and Other Charges, Net Restructuring And Related Activities Disclosure [Text Block] Segment Reporting [Abstract] Segment Information Segment Reporting Disclosure [Text Block] Earnings Per Share Earnings Per Share [Text Block] Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract] Accumulated Other Comprehensive Loss Comprehensive Income Note [Text Block] Equity Method Investments And Joint Ventures [Abstract] Investments Equity Method Investments Disclosure [Text Block] Inventory Disclosure [Abstract] Inventories Inventory Disclosure [Text Block] Debt Disclosure [Abstract] Debt Debt Disclosure [Text Block] Compensation And Retirement Disclosure [Abstract] Pension and Other Postretirement Benefits Pension And Other Postretirement Benefits Disclosure [Text Block] Fair Value Disclosures [Abstract] Derivatives and Other Financial Instruments Fair Value Disclosures [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Leases [Abstract] Leasing Lessee Operating Leases [Text Block] Commitments And Contingencies Disclosure [Abstract] Contingencies Commitments And Contingencies Disclosure [Text Block] Other Income And Expenses [Abstract] Other Income, Net Other Nonoperating Income And Expense [Text Block] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Principles of Consolidation Consolidation Policy [Text Block] Schedule of restructuring charges, net before income tax not allocated to reportable segment. Schedule of Restructuring and Other Charges, Net by Reportable Segments, Pretax Schedule Of Restructuring Charges Net Before Income Tax Not Allocated To Reportable Segment Table [Text Block] Activity and Reserve Balances for Restructuring Charges Schedule Of Restructuring Reserve By Type Of Cost [Text Block] Schedule of Operating Results of Alcoa's Reportable Segments Schedule Of Segment Reporting Information By Segment [Text Block] Schedule of segment reporting information to consolidate net income loss attributable to parent. Schedule of Segment Adjusted EBITDA to Consolidated Net Income Attributable to Alcoa Corporation Schedule Of Segment Reporting Information To Consolidate Net Income Loss Attributable To Parent Table [Text Block] Schedule of Sales by Product Division Schedule Of Entity Wide Information Revenue From External Customers By Products And Services [Text Block] Schedule of Computation of Basic and Diluted EPS Attributable to Alcoa Corporation Common Shareholders Schedule Of Earnings Per Share Basic And Diluted Table [Text Block] Summary of Changes in Accumulated Other Comprehensive (Loss) Income by Component Schedule Of Accumulated Other Comprehensive Income Loss Table [Text Block] Summary of Unaudited Financial Information for Alcoa Corporation's Equity Investments Equity Method Investments [Text Block] Schedule of Inventory Components Schedule Of Inventory Current Table [Text Block] Components of Net Periodic Benefit Cost Schedule Of Net Benefit Costs Table [Text Block] Schedule of Detail for Level 1 and 3 Derivatives Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Table [Text Block] Schedule of outstanding quantities of derivative instruments. Schedule of Outstanding Quantities of Derivative Instruments Schedule Of Outstanding Quantities Of Derivative Instruments Table [Text Block] Tabular disclosure of quantitative information about the inputs used in the fair value measurement of assets and liabilities. This disclosure may include, but is not limited to, the fair value of the asset or liability, valuation technique used to measure fair value, the inputs used to measure fair value, the ranges of the inputs, and the weighted averages of the inputs. Schedule of Quantitative Information for Level 3 Derivative Contracts Fair Value Inputs Assets Liabilities Quantitative Information Table [Text Block] Schedule of Fair Values of Level 3 Derivative Instruments Recorded as Assets and Liabilities Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value [Text Block] Tabular disclosure of the fair value measurement of assets and liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income (loss) and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of asset and liability. Fair Value Assets Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Text Block Fair Value Assets Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Text Block] Schedule of Carrying Values and Fair Values of Other Financial Instruments Fair Value By Balance Sheet Grouping [Text Block] Schedule of Income Taxes Schedule Of Components Of Income Tax Expense Benefit Table [Text Block] Schedule of Lease Expense and Operating Cash Flows Lease Cost Table [Text Block] Schedule of weighted average lease term and weighted average discount rate. Schedule of Weighted Average Lease Term and Weighted Average Discount Rate Schedule Of Weighted Average Lease Term And Weighted Average Discount Rate Table [Text Block] Schedule of aggregate right-of use assets and related lease obligations. Schedule of Aggregate Right-of Use Assets and Related Lease Obligations Schedule Of Aggregate Right Of Use Assets And Related Lease Obligations Table [Text Block] Schedule of Future Cash Flows Related to Operating Lease Obligations Lessee Operating Lease Liability Maturity Table [Text Block] Tabular disclosure of changes in carrying value of recorded environmental remediation reserves. Schedule of Changes in Carrying Value of Recorded Environmental Remediation Reserves Schedule Of Changes In Carrying Value Of Recorded Environmental Remediation Reserves Table [Text Block] Tabular disclosure of estimate timing of cash outflows on environmental reserves. Schedule of Estimate Timing of Cash Outflows on Environmental Reserves Schedule Of Estimate Timing Of Cash Outflows On Environmental Reserves Table [Text Block] Schedule of Other Income, Net Schedule Of Other Nonoperating Income Expense Table [Text Block] Basis of Presentation [Line Items] Basis Of Presentation [Table] Basis Of Presentation [Table] Basis Of Presentation [Table] Ownership Ownership [Axis] Ownership Ownership [Domain] Alcoa world alumina and chemicals. AWAC [Member] Alcoa World Alumina And Chemicals [Member] Legal Entity Legal Entity [Axis] Entity Entity [Domain] Alcoa corporation. Alcoa Corporation [Member] Alcoa Corporation [Member] Investment, Name Schedule Of Equity Method Investment Equity Method Investee Name [Axis] Investment, Name Equity Method Investee Name [Domain] Alumina limited. Alumina Limited [Member] Alumina Limited [Member] Basis Of Presentation [Line Items] Basis Of Presentation [Line Items] Ownership interest percentage Minority Interest Ownership Percentage By Parent Non-controlling interest, ownership percentage Minority Interest Ownership Percentage By Noncontrolling Owners Disposal group including discontinued operation other postretirement benefit liabilities assumed. Liabilities recorded from disposal group including discontinued operation. Discontinued Operations And Disposal Groups [Abstract] Business disposition. Schedule Of Business Dispositions By Disposition [Table] Schedule Of Business Dispositions By Disposition [Table] Schedule Of Business Dispositions By Disposition [Table] Disposal Group Name Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Axis] Disposal Group Name Disposal Groups Including Discontinued Operations Name [Domain] Warrick Rolling Mill. Warrick Rolling Mill [Member] Warrick Rolling Mill [Member] Disposal Group Classification Disposal Group Classification [Axis] Disposal Group Classification Disposal Group Classification [Domain] Held for Sale [Member] Disposal Group Heldforsale Not Discontinued Operations [Member] Business Disposition [Line Items] Business Disposition [Line Items] Total consideration Disposal Group Including Discontinued Operation Consideration Assumption of other postretirement benefit liabilities Disposal Group Including Discontinued Operation Other Postretirement Benefit Liabilities Assumed Net gain from asset sales Remaining reserve Liabilities Recorded From Disposal Group Including Discontinued Operation Payments against the reserve Accrual For Environmental Loss Contingencies Payments1 Aluminum smelter and power plant production per annum Number of employees. Number of employees Entity Number Of Employees Production of aluminum smelter and power plants (metric ton per year) Aluminum Smelter And Power Plant Production Per Annum Number of employees Number Of Employees Schedule Of Restructuring And Related Costs [Table] Schedule Of Restructuring And Related Costs [Table] Restructuring Type Restructuring Cost And Reserve [Axis] Type of Restructuring Type Of Restructuring [Domain] Legal disputes related to two thousand nineteen divestiture. Legal Disputes Related to 2019 Divestiture [Member] Legal Disputes Related To Two Thousand Nineteen Divestiture [Member] Real Estate Property Ownership Real Estate Properties [Axis] Real Estate Properties Real Estate Properties [Domain] Avilés and La Coruña (Spain) aluminum facilities. Avilés and La Coruña Facilities [Member] Aviles And La Coruna Spain Aluminum Facilities [Member] MRN. MRN [Member] M R N [Member] Estimated contract costs. Estimated Contract Costs Estimated Contract Costs [Member] Wenatchee Smelter. Wenatchee Smelter [Member] Wenatchee Smelter [Member] Severance and facility exit cost. Severance and Exit Costs [Member] Severance And Facility Exit Cost [Member] Additional contract costs. Contract Termination [Member] Additional Contract Costs [Member] Wenatchee and Intalco facility. Wenatchee (Washington) and Intalco (Washington) [Member] Wenatchee And Intalco Facility [Member] Permanent Close [Member] Facility Closing [Member] Miscellaneous charges. Other Item Charges [Member] Other Miscellaneous Charges [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost And Reserve [Line Items] Asset impairment charges Asset Impairment Charges Settlement and curtailment of certain other postretirement benefits Defined Benefit Plan Recognized Net Gain Loss Due To Settlements And Curtailments1 Segments Statement Business Segments [Axis] Segments Segment [Domain] Bauxite. Bauxite [Member] Bauxite [Member] Alumina. Alumina [Member] Alumina [Member] Aluminum products segment. Aluminum Segment [Member] Aluminum Products Segment [Member] Consolidation Items Consolidation Items [Axis] Consolidation Items Consolidation Items [Domain] Operating Segments [Member] Operating Segments [Member] Corporate [Member] Corporate Non Segment [Member] Restructuring and other charges, net Restructuring and other charges net. Severance and Employee Termination Costs [Member] Employee Severance [Member] Other exit costs. Other Costs [Member] Other Exit Costs [Member] Restructuring reserve beginning balance Restructuring Reserve Restructuring and other charges, net Restructuring And Other Charges Net Cash payments Payments For Restructuring Reversals and other Restructuring Reserve Translation And Other Adjustment Restructuring reserve ending balance Noncurrent portion of the reserve Restructuring Reserve Noncurrent Number of reportable segments Number Of Reportable Segments Segment reporting information depreciation depletion and amortization expenses. Segment reporting information equity in net income of equity method investees of segments. Schedule Of Segment Reporting Information By Segment [Table] Schedule Of Segment Reporting Information By Segment [Table] Aluminum. Aluminum [Member] Aluminum [Member] Related Party Related Party Transactions By Related Party [Axis] Related Party Related Party [Domain] Third party sales. Third-Party Sales [Member] Third Party Sales [Member] Intersegment Eliminations [Member] Intersegment Elimination [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Third-party sales Segment Reporting Information Unrelated Party Sales Intersegment sales Segment Reporting Information Intersegment Revenues Total sales Revenue From Contract With Customer Including Assessed Tax Segment Adjusted EBITDA Adjusted Ebitda Depreciation, depletion, and amortization Segment Reporting Information Depreciation Depletion And Amortization Expenses Equity (loss) income Segment Reporting Information Equity In Net Income Of Equity Method Investees Of Segments Other [Member] Material Reconciling Items [Member] Total Segment Adjusted EBITDA Transformation Segment Reporting Information Transformation Intersegment eliminations Segment Reporting Information Intersegment Eliminations Corporate expenses Segment Reporting Information Corporate Expenses Provision for depreciation, depletion, and amortization Restructuring and other charges, net (D) Interest expense Other income, net (P) Other Segment Reporting Information Other Income Expense Net Provision for income taxes Net income attributable to noncontrolling interest Disaggregation Of Revenue [Table] Disaggregation Of Revenue [Table] Product and Service Product Or Service [Axis] Product and Service Products And Services [Domain] Primary aluminum. Primary Aluminum [Member] Primary Aluminum [Member] Flat rolled aluminum. Flat-Rolled Aluminum [Member] Flat Rolled Aluminum [Member] Energy. Energy [Member] Energy [Member] Other products. Other Products [Member] Other Products [Member] Disaggregation Of Revenue [Line Items] Disaggregation Of Revenue [Line Items] Sales Net income attributable to Alcoa Corporation Average shares outstanding – basic Weighted Average Number Of Shares Outstanding Basic Effect of dilutive securities: Weighted Average Number Diluted Shares Outstanding Adjustment [Abstract] Stock options Incremental Common Shares Attributable To Share Based Payment Arrangements Stock units Incremental Common Shares Attributable To Nonvested Shares With Forfeitable Dividends Average shares outstanding – diluted Weighted Average Number Of Diluted Shares Outstanding Weighted average exercise price of underwater options. Shares that would have been included in diluted earnings per share calculation. Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Stock Options [Member] Employee Stock Option [Member] Stock awards and stock options. Stock Awards and Stock Options [Member] Stock Awards And Stock Options [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Weighted average exercise price of options Weighted Average Exercise Price Of Underwater Options Common shares equivalents that would have been included in diluted average shares outstanding Shares That Would Have Been Included In Diluted Earnings Per Share Calculation Equity [Abstract] Accumulated Other Comprehensive Income Loss [Table] Accumulated Other Comprehensive Income Loss [Table] Alcoa Corporation [Member] Parent [Member] Derivative Instrument Derivative Instrument Risk [Axis] Derivative Contract Derivative Contract Type [Domain] Aluminum contracts. Aluminum Contracts [Member] Aluminum Contracts [Member] Finance related derivative. Financial Contracts [Member] Finance Related Derivative [Member] Interest Rate Contracts [Member] Interest Rate Contract [Member] Foreign Exchange Contract [Member] Foreign Exchange Contract [Member] Accumulated Other Comprehensive Income Loss [Line Items] Accumulated Other Comprehensive Income Loss [Line Items] Pension and other postretirement benefits (K) Pension And Other Postretirement Benefit Expense [Abstract] Balance at beginning of period Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax Unrecognized net actuarial loss and prior service cost/benefit Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments And Tax Tax benefit Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Before Reclassification Adjustments Tax Total Other comprehensive (loss) income before reclassifications, net of tax Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments Net Of Tax Amortization of net actuarial loss and prior service cost/benefit Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans Before Tax Tax expense Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans Tax Total amount reclassified from Accumulated other comprehensive loss, net of tax Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans Net Of Tax Total Other comprehensive income Balance at end of period Foreign currency translation Foreign Currency Translation [Abstract] Balance at beginning of period Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax Other comprehensive income (loss) Balance at end of period Cash flow hedges (L) Effect Of Cash Flow Hedges On Results Of Operations [Abstract] Balance at beginning of period Aoci Loss Cash Flow Hedge Cumulative Gain Loss After Tax Net change from periodic revaluations Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax Tax benefit Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax Total Other comprehensive (loss) income before reclassifications, net of tax Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax Net amount reclassified to earnings Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax Tax expense Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax Total amount reclassified from Accumulated other comprehensive loss, net of tax Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax Total Other comprehensive (loss) income Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Balance at end of period Total Accumulated other comprehensive loss This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied before reconciling adjustments. This item represents adjustments made to determine the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Schedule Of Investments [Abstract] Schedule Of Equity Method Investments [Table] Schedule Of Equity Method Investments [Table] Mining. Mining [Member] Mining [Member] Other [Member] Ma'aden joint venture. Ma'aden Joint Venture [Member] Maaden Joint Venture [Member] Equity Method Investment, Nonconsolidated Investee Equity Method Investment Nonconsolidated Investee [Axis] Equity Method Investment, Nonconsolidated Investee Equity Method Investment Nonconsolidated Investee [Domain] Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member] Equity Method Investment Nonconsolidated Investee Or Group Of Investees [Member] Schedule of Equity Method Investments [Line Items] Schedule Of Equity Method Investments [Line Items] Sales Revenues Cost of goods sold Cost Of Revenue Net income (loss) Equity in net income (loss) of affiliated companies, before reconciling adjustments Income Loss From Equity Method Investments Before Reconciling Adjustments Other Income Loss From Equity Method Investments Reconciling Adjustments Alcoa Corporation’s equity in net income (loss) of affiliated companies Income Loss From Equity Method Investments Ownership interest in joint venture. Ma'aden Alcoa joint venture. Maaden Alcoa Joint Venture [Member] Maaden Alcoa Joint Venture [Member] Ma’aden. Ma'aden [Member] Maaden [Member] Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] SAUDI ARABIA SAUDI ARABIA Elysis Limited Partnership. ELYSIS TM Limited Partnership [Member] Elysis Limited Partnership [Member] Mineracao Rio Do Norte S.A. Mineração Rio do Norte S.A [Member] Mineracao Rio Do Norte S A [Member] Brazil [Member] BRAZIL Ownership interest in joint venture Ownership Interest In Joint Venture Basis in investment, due to share of losses. Equity method investment unrecognized gain (loss). Basis in investment, due to share of losses Basis In Investment Due To Share Of Losses Unrecognized losses Equity Method Investment Unrecognized Gain Loss Additional cash to be received upon satisfying post closing conditions. Proceeds from Sale of Long-term Investments Proceeds From Sale Of Longterm Investments Asset impairment charges Additional cash to be received upon satisfying post closing conditions Additional Cash To Be Received Upon Satisfying Post Closing Conditions Finished goods Inventory Finished Goods Net Of Reserves Work-in-process Inventory Work In Process Net Of Reserves Bauxite and alumina Other Inventory Net Of Reserves Purchased raw materials Inventory Raw Materials Net Of Reserves Operating supplies Inventory Supplies Net Of Reserves Inventories, total Debt Instrument [Table] Debt Instrument [Table] Credit Facility Credit Facility [Axis] Credit Facility Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Line of credit facility, outstanding borrowings Line Of Credit Line of credit facility, maturity date Line Of Credit Facility Expiration Date1 Letters of credit Debt Instrument Face Amount Amounts borrowed under the credit facility Proceeds From Long Term Lines Of Credit Schedule Of Defined Benefit Plans Disclosures [Table] Schedule Of Defined Benefit Plans Disclosures [Table] Retirement Plan Type Retirement Plan Type [Axis] Retirement Plan Type Retirement Plan Type [Domain] Pension Benefits [Member] Pension Plans Defined Benefit [Member] Other Postretirement Benefits [Member] Other Postretirement Benefit Plans Defined Benefit [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Service cost Defined Benefit Plan Service Cost Interest cost Defined Benefit Plan Interest Cost Expected return on plan assets Defined Benefit Plan Expected Return On Plan Assets Recognized net actuarial loss Defined Benefit Plan Amortization Of Gains Losses Amortization of prior service cost Defined Benefit Plan Amortization Of Prior Service Cost Credit Settlements Defined Benefit Plan Recognized Net Gain Loss Due To Settlements1 Curtailments Defined Benefit Plan Recognized Net Gain Loss Due To Curtailments Net periodic benefit cost Defined Benefit Plan Net Periodic Benefit Cost Minimum required cash contribution to pension plan. Scenario Statement Scenario [Axis] Scenario Scenario Unspecified [Domain] Forecast [Member] Scenario Forecast [Member] Retirement Plan Sponsor Location Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location Retirement Plan Sponsor Location [Domain] Domestic Plan Domestic Plan [Member] United States [Member] UNITED STATES Non-U.S. [Member] Foreign Plan [Member] Minimum required cash contribution to pension plans Minimum Required Cash Contribution To Pension Plan Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Derivative instrument level 1. Level 1 Derivative Instruments [Member] Derivative Instrument Level1 [Member] Derivative instrument level 1 and 2. Level 1 and 2 Derivative Instruments [Member] Derivative Instrument Level1 And2 [Member] Derivative instrument level 3. Level 3 Derivative Instruments [Member] Derivative Instrument Level3 [Member] Derivative instrument level 1 and 3. Level 1 and 3 Derivative Instruments [Member] Derivative Instrument Level1 And3 [Member] Derivative instrument level 2. Level 2 Derivative Instruments [Member] Derivative Instrument Level2 [Member] Noncontrolling and equity interest. Non-controlling and Equity Interest [Member] Noncontrolling And Equity Interest [Member] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Derivative Assets Derivative Assets Derivative Liabilities Derivative Liabilities Derivative Assets Current Derivative Liabilities Current Derivative Assets Noncurrent Derivative Liabilities Noncurrent Unrealized loss recognized in Other comprehensive loss Realized loss reclassed from Other comprehensive loss to earnings Hedging Designation Hedging Designation [Axis] Hedging Designation Hedging Designation [Domain] Derivatives Designated as Hedging Instruments [Member] Designated As Hedging Instrument [Member] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Sales [Member] Sales [Member] Cost of Goods Sold [Member] Cost Of Sales [Member] Commodity Contract Commodity Contract [Member] Fair Value Hierarchy and NAV Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value Inputs Level1 [Member] San Ciprian (Spain) Strike [Member] SPAIN Foreign Exchange Forward Foreign Exchange Forward [Member] U.S. dollar Aluminum Sales, Australia [Member] AUSTRALIA Euro Power Purchases, Norway [Member] NORWAY Derivatives Not Designated as Hedging Instruments [Member] Nondesignated [Member] Power Related Derivative [Member]. Power Contract [Member] Power Related Derivative [Member] Hedging Relationship Derivative Instruments Gain Loss By Hedging Relationship [Axis] Hedging Relationship Hedging Relationship [Domain] Cash Flow Hedging [Member] Cash Flow Hedging [Member] Outstanding aluminum derivative instruments. Outstanding quantities of derivative instruments Outstanding Aluminum Derivative Instruments Outstanding quantities of derivative instruments Derivative instrument, maturity month and year. Derivative instruments, expiration month and year Derivative Instrument Maturity Month And Year Derivative, expiration date Derivative Maturity Dates Number of financial contracts. Number of financial contracts Number Of Financial Contracts Offsetting [Abstract] Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Table] Financial Instrument Financial Instrument [Axis] Financial Instruments Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] Energy Contracts [Member] Energy Related Derivative [Member] Measurement Input Type Measurement Input Type [Axis] Measurement Input Type Measurement Input Type [Domain] MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 4 Million MWh Per Year. MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 4 Million MWh Per Year [Member] M Wh Of Energy Needed To Produce Forecasted Mt Of Aluminum At Rate Of4 Million M Wh Per Year [Member] MWh of energy needed to produces forecasted Mt of aluminum at rate of 18 million MWh per year. MWh of Energy Needed to Produce Forecasted Mt of Aluminum at Rate of 18 Million MWh Per Year [Member] M Wh Of Energy Needed To Produces Forecasted Mt Of Aluminum At Rate Of18 Million M Wh Per Year [Member] Estimated spread between the respective thirty year debt yield of Alcoa Corporation and the counterparty. Estimated Spread Between The Respective 30-Year Debt Yield Of Alcoa Corporation And The Counterparty [Member] Estimated Spread Between The Respective Thirty Year Debt Yield Of Alcoa Corporation And The Counterparty [Member] Interrelationship of forward energy price, LME forward price and consumer price index. Interrelationship of Forward Energy Price, LME Forward Price and Consumer Price Index [Member] Interrelationship Of Forward Energy Price L M E Forward Price And Consumer Price Index [Member] Level 3 [Member] Fair Value Inputs Level3 [Member] Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Derivative Assets, Fair value Derivative Liabilities, Fair value Derivative Instruments And Hedging Activities Disclosure [Abstract] Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Balance Sheet Location Balance Sheet Location [Axis] Balance Sheet Location Balance Sheet Location [Domain] Current assets. Fair Value of Derivative Contracts - Current [Member] Current Assets [Member] Current liabilities. Fair Value of Derivative Contracts - Current [Member] Current Liabilities [Member] Noncurrent liabilities. Fair Value of Derivative Contracts - Noncurrent [Member] Noncurrent Liabilities [Member] Embedded credit derivative. Embedded Credit Derivative [Member] Embedded Credit Derivative [Member] Derivative Instruments Gain Loss [Line Items] Derivative Instruments Gain Loss [Line Items] Total Asset Derivatives Fair value liability derivatives Amount of (loss) gain expected to be recognized into earnings over the next 12 months Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months Aluminum forecasted sales designated as fair value hedges in kilo metric ton. Aluminum forecast sales Aluminum Forecasted Sales Designated As Fair Value Hedges In Kilo Metric Ton Fair value measurement with unobservable inputs reconciliation recurring basis asset increase decrease other. Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Table] Other Expense (Income), Net [Member] Nonoperating Income Expense [Member] Other Income, Net [Member] Other Income [Member] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair value measurement, Assets, Beginning balance Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Fair value measurement, Assets Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 Other comprehensive income (unrealized) Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss Fair value measurement, Assets, Other Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Increase Decrease Other Fair value measurement, Assets, Ending balance Fair value measurement with unobservable inputs reconciliation recurring basis liabilities increase decrease other. Fair value liabilities measured on recurring basis gain loss included in other expenses, net. Fair value measurement, Liabilities, Beginning balance Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value Fair value measurement, Liabilities Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings Other comprehensive income (unrealized) Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Other Comprehensive Income Fair value measurement, Liabilities, Other Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liabilities Increase Decrease Other Fair value measurement, Liabilities, Ending balance Fair value measurement, Liabilities, Other income, net Fair Value Liabilities Measured On Recurring Basis Gain Loss Included In Other Expenses Net Derivative [Table] Derivative [Table] Measurement Basis Fair Value By Measurement Basis [Axis] Fair Value Disclosure Item Amounts [Default] Portion At Fair Value Fair Value Disclosure [Member] Fair Value Measurement Fair Value Disclosure Item Amounts [Domain] Carrying Value [Member] Carrying Reported Amount Fair Value Disclosure [Member] Fair Value [Member] Estimate Of Fair Value Fair Value Disclosure [Member] Derivative [Line Items] Derivative [Line Items] Cash and cash equivalents Cash And Cash Equivalents Fair Value Disclosure Restricted cash Restricted Cash Short-term borrowings Short Term Borrowings Long-term debt due within one year Debt Instrument Fair Value Long-term debt, less amount due within one year Long Term Debt Fair Value Income tax expense benefit on losses in jurisdictions with full valuation reserves. Income taxes. Income taxes. Income Taxes [Table] Income Taxes [Table] Iceland [Member] ICELAND Income Taxes [Line Items] Income Taxes [Line Items] Effective federal statutory tax rate Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate Income tax expense benefits on losses valuation reserves Income Tax Expense Benefits On Losses Valuation Reserves Estimated annualized effective tax rate. Income tax expense (benefit) from estimated annualized effective tax rate. Unfavorable (favorable) impact income tax expense benefit. Discrete tax (benefit) expense. Income before income taxes Estimated annualized effective tax rate Estimated Annualized Effective Tax Rate Income tax expense Income Tax Expense Benefit From Estimated Annualized Effective Tax Rate Unfavorable (favorable) tax impact related to losses in jurisdictions with no tax benefit Unfavorable Favorable Impact Income Tax Expense Benefit Discrete tax expense (benefit) Discrete Tax Benefit Expense Provision for income taxes Net deferred tax assets Deferred Tax Assets Liabilities Net Leases. Leases. Leases [Table] Leases [Table] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Leases [Line Items] Leases [Line Items] Remaining lease term Lessee Operating Lease Remaining Lease Term Costs from operating leases Operating Lease Cost Variable lease payments Variable Lease Cost Short-term rental expense Short Term Lease Cost Weighted average lease term for operating leases (years) Operating Lease Weighted Average Remaining Lease Term1 Weighted average discount rate for operating leases Operating Lease Weighted Average Discount Rate Percent Properties, plants and equipment, net Operating Lease Right Of Use Asset Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease Right Of Use Asset Statement Of Financial Position Extensible List Other current liabilities Operating Lease Liability Current Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Operating Lease Liability Current Statement Of Financial Position Extensible List Other noncurrent liabilities and deferred credits Operating Lease Liability Noncurrent Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Operating Lease Liability Noncurrent Statement Of Financial Position Extensible List Total operating lease liabilities Operating Lease Liability New leases Right Of Use Asset Obtained In Exchange For Operating Lease Liability 2022 (excluding the three months ended March 31) Lessee Operating Lease Liability Payments Remainder Of Fiscal Year 2023 Lessee Operating Lease Liability Payments Due Next Twelve Months 2024 Lessee Operating Lease Liability Payments Due Year Two 2025 Lessee Operating Lease Liability Payments Due Year Three 2026 Lessee Operating Lease Liability Payments Due Year Four Thereafter Lessee Operating Lease Liability Payments Due After Year Four Total lease payments (undiscounted) Lessee Operating Lease Liability Payments Due Less: discount to net present value Lessee Operating Lease Liability Undiscounted Excess Amount Total Accrual for environmental loss contingencies foreign currency translation gain (loss) and other. Beginning balance Accrual For Environmental Loss Contingencies Liabilities incurred Accrual For Environmental Loss Contingencies Charges To Expense For New Losses Cash payments Reversals of previously recorded liabilities Accrual For Environmental Loss Contingencies Increase Decrease For Revision In Estimates Foreign currency translation and other Accrual For Environmental Loss Contingencies Foreign Currency Translation Gain Loss And Other Ending balance Loss Contingencies [Table] Loss Contingencies [Table] Massena, New York. Massena, New York [Member] Massena New York [Member] Sherwin, TX [Member] Sherwin, Texas [Member] Sherwin T X [Member] Other sites. Other Sites [Member] Other Sites [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Environmental remediation reserve balance, current Accrued Environmental Loss Contingencies Current Liabilities incurred Reversals of previously recorded liabilities Accrual for environmental loss contingencies undiscounted one to five year. 2022 (excluding the three months ended March 31, 2022) Accrual For Environmental Loss Contingencies Undiscounted Due In Remainder Of Fiscal Year 2023 - 2027 Accrual For Environmental Loss Contingencies Undiscounted One To Five Year Thereafter Accrual For Environmental Loss Contingencies Undiscounted Due After Fifth Year Total Accrual environmental loss active remediation future remediation for significant individual sites. Active or future remediation for significant sites Accrual Environmental Loss Active Remediation Future Remediation For Significant Individual Sites Environmental remediation work completion period. Environmental remediation work completion period Environmental Remediation Work Completion Period Expected additional term for reuse of residue bed. Expected additional term for reuse of residue bed Expected Additional Term For Reuse Of Residue Bed Number of remediation projects. Number of remediation projects Number Of Remediation Projects Accrued environmental reserves Percentage of penalty on amount of additional taxes due. Tax credit previously claimed and disallowed by tax authority. Alcoa World Alumina Brasil (AWAB). Alcoa World Alumina Brasil [Member] Alcoa World Alumina Brasil [Member] Income Tax Authority, Name Income Tax Authority Name [Axis] Income Tax Authority, Name Income Tax Authority Name [Domain] Brazilian Federal Revenue Office. Brazilian Federal Revenue Office [Member] Brazilian Federal Revenue Office [Member] Income Tax Authority Income Tax Authority [Axis] Income Tax Authority Income Tax Authority [Domain] Foreign Jurisdiction [Member] Foreign Country [Member] Australian Taxation Office [Member] Australian Taxation Office [Member] Consolidated Entities Consolidated Entities [Axis] Consolidated Entities Consolidated Entities [Domain] Alcoa of Australia limited. AofA [Member] Alcoa Of Australia Limited [Member] Restructuring Plan Restructuring Plan [Axis] Restructuring Plan Restructuring Plan [Domain] Aviles and La Coruna Facilities. Aviles And La Coruna Facilities [Member] Aviles And La Coruna Facilities [Member] Disallowed tax credits Tax Credit Previously Claimed And Disallowed By Tax Authority Percentage of penalty of the gross disallowed amount Percentage Of Penalty On Amount Of Additional Taxes Due Value added tax receivable Income Tax Credits And Adjustments Charge recorded in provision for income taxes to establish liability for estimated loss Income Tax Examination Estimate Of Possible Loss Income tax payable, possible unrecorded assessed amount from taxing authority. Notices include claims for compounded interest on the tax amount. Tax assessment deposit. Proposed administrative penalties. Payment of disputed tax amount, percentage. Assessed income tax amount exclusive of interest and penalties. Payment amount refund percentage. Additional income tax payable, exclusive of interest and penalties Income Tax Payable Possible Unrecorded Assessed Amount From Taxing Authority Notices include claims for compounded interest on the tax amount Notices Include Claims For Compounded Interest On The Tax Amount Proposed administrative penalties Proposed Administrative Penalties Payment of dispute resolution practices income tax percentage Payment Of Disputed Tax Amount Percentage Assessed income tax amount exclusive of interest and penalties Assessed Income Tax Amount Exclusive Of Interest And Penalties Payment amount refund percentage Payment Amount Refund Percentage Reduction in current year cash tax payment Tax Adjustments Settlements And Unusual Provisions Other noncurrent liabilities and deferred credits Tax assessment deposit Tax Assessment Deposit Restructuring Charges Restructuring Charges This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied and is reflected as nonoperating income on the Statement of Consolidated Operations. Equity income Income Loss From Equity Method Investments Nonoperating Foreign currency losses (gains), net Foreign Currency Transaction Gain Loss Before Tax Net loss (gain) from asset sales Gain Loss On Disposition Of Assets Net gain on mark-to-market derivative instruments (L) Unrealized Gain Loss On Derivatives Non-service costs – Pension & OPEB (K) Pension And Other Postretirement Benefit Expense Other Other Nonoperating Income Expense Other income , net Other non operating income expense. Schedule Of Other Non operating Income Expense [Table] Schedule Of Other Non Operating Income Expense [Table] Schedule Of Other Non Operating Income Expense [Table] Other Non Operating Income Expense [Line Items] Other Non Operating Income Expense [Line Items]