Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Cash payments to settle liabilities Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Share-Based Liabilities Paid Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Range [Domain] Statistical Measurement [Domain] Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Adjustment to prime rate Debt Instrument, Variable Interest Rate, Adjustment to Prime Rate Debt Instrument, Variable Interest Rate, Adjustment to Prime Rate Senior Notes due August 2031 Senior Notes due August 2031 [Member] Senior Notes due August 2031 Equity Method Investments Equity Method Investments [Member] Subsequent Event Subsequent Event [Member] Document Fiscal Year Focus Document Fiscal Year Focus Other Other Restructuring Costs Net Fair Value Assets/Liabilities Derivative assets (liabilities), at fair value, net Derivative Assets (Liabilities), at Fair Value, Net Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Estimated fair value of certain financial instruments that are not recorded at fair value on a recurring basis Fair Value Measurements, Nonrecurring [Table Text Block] Adjustment to Compensation, Amount Adjustment to Compensation Amount Other Assets, Fair Value Disclosure Other Assets, Fair Value Disclosure Segment Reporting [Abstract] Segment Reporting [Abstract] South America South America [Member] Restructuring Plan [Axis] Restructuring Plan [Axis] From 2008 to 2014 From 2008 to 2014 [Member] From 2008 to 2014 Common stock, no par value; Unlimited number of shares authorized; 606,333,333 shares issued and outstanding as of June 30, 2026, and March 31, 2026 Common Stock, Value, Issued Interest expense and amortization of debt issuance costs Interest expense and amortization of debt issuance costs Interest Expense, Operating and Nonoperating 8. POSTRETIREMENT BENEFIT PLANS Retirement Benefits [Text Block] Series 2026A Bonds, due March 2033 Series 2026A Bonds, due March 2033 [Member] Series 2026A Bonds, due March 2033 Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Expected return on assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Realized losses (gains) on change in fair value of derivative instruments, net Realized Gains Losses On Derivative Net Realized gains losses on derivative net. Derivative Instrument [Axis] Derivative Instrument [Axis] Maturities of long-term debt outstanding Maturities of Long-Term Debt [Abstract] Other Other Noninterest Expense Measurement Frequency [Axis] Measurement Frequency [Axis] Accounts receivable, allowance for credit loss Accounts Receivable, Allowance for Credit Loss Document and Entity Information [Abstract] Document and Entity Information [Abstract] -- None. No documentation exists for this element. -- Proceeds from sales of assets, third party, net of transaction fees and hedging Proceeds from Sale of Productive Assets Amendment Flag Amendment Flag Consolidated Entities [Axis] Consolidated Entities [Axis] Current liabilities: Liabilities, Current [Abstract] Restructuring and impairment expenses, net Restructuring and impairment expenses, net Restructuring Costs and Asset Impairment Charges Summary of notional amount Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding AV Minerals (Netherlands) N.V. AV Minerals (Netherlands) N.V. [Member] AV Minerals (Netherlands) N.V. Fair value of financial instruments and commodity contracts Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract] Proceeds from equity contribution Proceeds from Contributed Capital Loss Contingencies [Table] Loss Contingencies [Table] Sublimit Line of Credit Facility, Maximum Borrowing Capacity, Sublimit Line of Credit Facility, Maximum Borrowing Capacity, Sublimit Series 2025A Bonds, due June 2032 Series 2025A Bonds, due June 2032 [Member] Series 2025A Bonds, due June 2032 Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax [Abstract] Liability for Unpaid Claim and Claim Adjustment Expense, Change [Table] Liability for Unpaid Claim and Claim Adjustment Expense, Change [Table] Currency Losses (Gains) Foreign Currency Disclosure [Text Block] Expected additional contribution to unfunded pension plan Additional Contributions To Unfunded Pension Plan Additional contributions to unfunded pension plan. Consolidated Entities [Domain] Consolidated Entities [Domain] Net change in pension and other benefits Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Derivative Liability, Master Netting Adjustment Derivative Liability, Master Netting Adjustment Derivative Liability, Master Netting Adjustment Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax China Loan, due December 2027 China Loan, due December 2027 [Member] China Loan, due December 2027 Capital expenditures Segment Reporting, Long-Lived Asset, Expenditure for Addition Catastrophic Event [Domain] Catastrophic Event [Domain] Notional amount Derivative, Notional Amount Restructuring Action Restructuring Action [Member] Restructuring Action [Member] Metal Contracts Metal Contracts [Member] Metal Contracts [Member] Components of net periodic benefit cost for postretirement benefit plans Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Period-end account balances with non-consolidated affiliates, shown as related party balances Schedule of Related Party Transactions [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Loss Contingencies Loss Contingencies [Line Items] Number of reportable segments Number of Reportable Segments Range of possible loss Loss Contingency, Range of Possible Loss, Portion Not Accrued Total current liabilities Total current liabilities Liabilities, Current Environmental Remediation Contingency [Domain] Environmental Remediation Contingency [Domain] 2025 Term Loan 2025 Term Loan [Member] 2025 Term Loan Europe Europe Segment [Member] Europe Segment Triggering Event [Domain] Triggering Event [Domain] Triggering Event Fair value of derivative instruments Derivative Liabilities, Current Derivative Liability, Current Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] 2025 Efficiency Plan 2025 Efficiency Plan [Member] 2025 Efficiency Plan Expected reclassification from AOCI to earnings Cash Flow Hedge Gain (Loss) to be Reclassified within 12 Months Entity Address, City or Town Entity Address, City or Town Share-based Compensation by Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Intangible assets, net Intangible Asset, Finite-Lived, after Accumulated Amortization Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Debt issuance costs Debt Issuance Costs, Gross Derivative, nonmonetary notional amount Derivative, Nonmonetary Notional Amount Parties Accounts receivable, net Accounts receivable, net — related parties Accounts and Other Receivables, Net, Current Schedule of inventories Inventory, Net [Abstract] Level 2 Instruments Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Accounts payable Accounts Payable and Accrued Liabilities, Current [Abstract] Loan facility, maximum capacity Line of Credit Facility, Maximum Borrowing Capacity Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Proceeds from insurance claims Proceeds from Insurance Settlement, Investing Activities Subsequent Event Type [Axis] Subsequent Event Type [Axis] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Subsidiary or Equity Method Investee, Sale of Stock, Type [Table] Subsidiary or Equity Method Investee, Sale of Stock, Type [Table] Recently Adopted Accounting Standards and Recently Issued Accounting Standards (Not Yet Adopted) New Accounting Pronouncements, Policy [Policy Text Block] Accrued capital expenditures Capital Expenditures Incurred but Not yet Paid Selected segment financial information Segment Reporting [Table Text Block] Non- controlling Interests Noncontrolling Interest [Member] (Gain) loss on sale or disposal of assets, net Gain (loss) on sale or disposal of assets, net Gain (Loss) on Disposition of Property Plant Equipment Use of Estimates and Assumptions Use of Estimates, Policy [Policy Text Block] Amortization of debt issuance costs and carrying value adjustments Amortization of Debt Issuance Costs Expected additional contribution to savings and defined contribution plans Defined Contribution Plan, Employer Discretionary Contribution Amount Unsecured Debt Unsecured Debt [Member] Related Party [Axis] Related and Nonrelated Parties [Axis] Pension and other benefits, tax provision (benefit) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Long-term debt, Carrying Value Outstanding principal amount Total debt - third parties (excluding short term borrowings), carrying value Long-Term Debt Notes receivable Notes Receivable, Fair Value Disclosure Copper Forward Contracts LME Copper and Zinc Forward Contracts [Member] Copper Forward Contracts [Member] Document Period End Date Document Period End Date Changes in assets and liabilities including assets and liabilities held for sale: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] (Gains) losses on remeasurement of monetary assets and liabilities, net Gain (Loss) on Remeasurement of Monetary Assets and Liabilities, Net Gain (loss) on remeasurement of monetary assets and liabilities net. Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Debt face amount Debt Instrument, Face Amount Cumulative restructuring charges through June 30, 2026 Restructuring and Related Cost, Cost Incurred to Date Quarterly amortization payments Debt Instrument, Quarterly Amortization Payments, Percent Debt Instrument, Quarterly Amortization Payments, Percent Interest rate, effective percentage Debt Instrument, Interest Rate, Effective Percentage China Bank Loans, due August 2027 Bank Loans, Due Through August 2027 [Member] Bank Loans, Due Through August 2027 Position [Axis] Position [Axis] Income tax provision (benefit) related to items of other comprehensive income Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Liabilities Liabilities, Fair Value Disclosure Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Asia Asia Segment [Member] Asia Segment Consolidation Items [Domain] Consolidation Items [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Name Outstanding Recovery, Individual Name Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total liabilities Total liabilities Liabilities Geographical [Domain] Geographical [Domain] Assets held for sale Asset, Held-for-Sale, Not Part of Disposal Group, Current Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Company Selected Measure Name Company Selected Measure Name Summary of condensed results of operations of equity method affiliates Equity Method Investment, Summarized Financial Information, Income Statement [Table Text Block] Tabular disclosure of the entity's share of earnings (losses) of equity method investments. Citibank Citibank [Member] Citibank Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Energy Contracts Energy Related Derivative [Member] Postretirement Benefit Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Long-term debt, principal Long-Term Debt, Gross Credit Facility [Domain] Credit Facility [Domain] Asset Class [Domain] Asset Class [Domain] Related Party Transactions [Abstract] Related Party Transactions [Abstract] OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Beginning balance, shares Ending balance, shares Shares, Issued Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Accrued postretirement benefits Liability, Defined Benefit Plan, Noncurrent Sierre flood losses, net of recoveries Loss from Catastrophes Underlying Security Market Price Change Underlying Security Market Price Change, Percent Proceeds from lines of credit Proceeds from Lines of Credit 2021 Term Loans 2021 Term Loans [Member] 2021 Term Loans Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current [Abstract] Start Up Cost Start Up Cost Start Up Cost Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Changzhou Plant Changzhou Plant [Member] Changzhou Plant Citi Facility Citi Facility [Member] Citi Facility Short-term borrowings Short-term borrowings Short-term borrowings Short-Term Debt Purchases of tolling services from Alunorf Purchase Of Tolling Services Purchase of tolling services. Other, net Other Nonoperating Income (Expense), Other Other Nonoperating Income (Expense), Other Award Timing Predetermined Award Timing Predetermined [Flag] Amount outstanding Letters of Credit Outstanding, Amount Employee-related expenses Severance Costs Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Total debt, Carrying Value Debt and Lease Obligation Derivative Asset, Noncurrent Derivative Asset, Noncurrent Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Natural Gas Swaps Natural Gas Swaps [Member] Natural gas swaps. Brazil Loans Brazil Loans [Member] Brazil Loans Antidumping Duties Antidumping Duties [Member] Antidumping Duties All Executive Categories All Executive Categories [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] 6.875% Senior Notes, due January 2030 6.875% Senior Notes, due January 2030 [Member] 6.875% Senior Notes, due January 2030 Components of net periodic benefit cost for all significant postretirement benefit plans Schedule of Net Benefit Costs [Table Text Block] Sierre flood Flood [Member] Aluminum Contracts Aluminium Contracts [Member] Aluminium contracts. Derivative Asset, Master Netting Adjustment Derivative Asset, Master Netting Adjustment Derivative Asset, Master Netting Adjustment Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Current portion of long-term debt Current portion of long-term debt Long-Term Debt and Lease Obligation, Current Unrealized gains (losses) on change in fair value of derivative instruments, net Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments 16. SEGMENT, GEOGRAPHICAL AREA, MAJOR CUSTOMER AND MAJOR SUPPLIER INFORMATION Segment Reporting [Text Block] Line of credit Long-Term Line of Credit Minimum Minimum [Member] Aluminum Forward Sales Contracts Aluminum Foward Sales Contracts [Member] Aluminum foward sales contracts Expiration Date Trading Arrangement Expiration Date Net (decrease) increase in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation 4 years Long-Term Debt, Maturity, Year Four Hedging Relationship [Axis] Hedging Relationship [Axis] LIABILITIES Liabilities [Abstract] 4. CONSOLIDATION Variable Interest Entity Disclosure [Text Block] Effect of exchange rate changes on cash Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement Location [Axis] Location, Statement of Income, Balance [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Total equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Third Party Nonrelated Party [Member] Unsecured debt Unsecured Debt Net periodic benefit cost Non-operating net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Other Income and Expenses [Abstract] Other Income and Expenses [Abstract] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Sale of stock, number of shares (in shares) Sale of Stock, Number of Shares Issued in Transaction Long-term debt, Unamortized Carrying Value Adjustments Debt Instrument, Unamortized Discount (Premium), Net Exercise Price Award Exercise Price Schedule of Restructuring and Related Costs [Table] Restructuring Cost [Table] INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Recurring Fair Value, Recurring [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Segment Reporting [Line Items] Segment Reporting [Line Items] Document Quarterly Report Document Quarterly Report Assets Derivative Asset [Abstract] Adjustment to reconcile proportional consolidation Adjustment To Eliminate Proportional Consolidation Adjustment to eliminate proportional consolidation. Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Interest Rate Swap Interest Rate Swap [Member] Finance lease obligations and other debt, due through April 2040(5) Other Debt, due through December 2020 [Member] Other Debt, due through December 2020 [Member] Europe Europe [Member] Lender Name [Axis] Lender Name [Axis] 6. DEBT Debt Disclosure [Text Block] Debt issuance costs Debt Issuance Costs, Net Less: Current portion of long-term debt Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Liabilities Derivative Liability [Abstract] Summary of restructuring reserve activity Restructuring and Related Costs [Table Text Block] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Investment in and advances to non-consolidated affiliates Equity Method Investments Equity Method Investments Balance as of beginning of period Balance as of end of period Restructuring Reserve Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Property insurance recoveries Property Insurance Recoveries Property Insurance Recoveries Term Loan Secured Debt [Member] Currency Exchange Contracts Foreign Exchange Contract [Member] Total expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date Thereafter Long-Term Debt, Maturity, after Year Five Schedule of other nonoperating income (expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] Deferred Compensation liability Deferred Compensation Share-Based Arrangements, Liability, Current and Noncurrent Stated rate Debt Instrument, Interest Rate, Stated Percentage Counterparty Name [Domain] Counterparty Name [Domain] Total equity of our common shareholder Equity, Attributable to Parent Restructuring Type [Axis] Restructuring Type [Axis] Contributions to employee benefit plans Defined Benefit Plan, Expected Future Employer Contributions [Abstract] ASSETS ASSETS Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Unfunded pension plans Defined Contribution Plan Employers Contribution To Unfunded Pension Plan Defined contribution plan employer's contribution to unfunded pension plan. Return of capital to our common shareholder Payments of Capital Distribution Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Professional fees Professional Fees Insider Trading Policies and Procedures [Line Items] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Deferred income taxes, net Deferred Income Tax Expense (Benefit) Selling, general and administrative expenses Selling, general and administrative expenses Selling, General and Administrative Expense Interest income Interest Income (Expense), Nonoperating Type of Restructuring [Domain] Type of Restructuring [Domain] Letter of Credit Letter of Credit [Member] Sale of stock, consideration Sale of Stock, Consideration Received Per Transaction Beverage packaging Beverage packaging [Member] Beverage packaging [Member] 15. COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Estimated litigation liability Estimated Litigation Liability Number of operating segments Number of Operating Segments September Oswego fire Fire [Member] RSUs Restricted Stock Units (RSUs) [Member] Entity Central Index Key Entity Central Index Key Repairs and clean-up costs Repairs And Clean-Up Costs (Reversal) Repairs And Clean-Up Costs (Reversal) Fair Value, Concentration of Risk, Financial Assets, Balance Sheet Groupings [Abstract] Fair Value, Concentration of Risk, Financial Assets, Balance Sheet Groupings [Abstract] Additional paid-in capital Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Other Operations Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Net cash (used in) provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Assets and Liabilities Held for Sale Assets and Liabilities Held for Sale Policy [Policy Text Block] Assets and Liabilities Held for Sale Policy Property insurance recoveries Property insurance recoveries Property And Other Insurance Recoveries Property And Other Insurance Recoveries Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Shareholder's equity: Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Investment, Name [Axis] Investment, Name [Axis] Expected long-term rate of return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets Designated as Hedging Instrument Designated as Hedging Instrument [Member] Restructuring Plan [Domain] Restructuring Plan [Domain] Deferred income tax assets Deferred income tax assets Deferred Income Tax Assets, Net Eliminations and Other Intersegment Eliminations [Member] SARs Stock Appreciation Rights (SARs) [Member] Stock Appreciation Rights (SARs) [Member] Debt Instruments [Table] Debt Instruments [Table] Debt Instruments. Variable rate Debt Instrument, Basis Spread on Variable Rate Accelerated depreciation Restructuring and Related Cost, Accelerated Depreciation Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] City Area Code City Area Code Net sales – intersegment Sales Revenue, Intersegment [Member] Sales Revenue, Intersegment [Member] Accumulated Other Comprehensive Loss (AOCI) Total AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] MUFG Facility MUFG Facility [Member] MUFG Facility Total debt - third parties (excluding short term borrowings), fair value Debt Instrument, Fair Value Disclosure Name Forgone Recovery, Individual Name Unrecognized compensation expense, weighted average period of recognition (years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Statement [Line Items] Statement [Line Items] Total assets Total assets Assets Assets Derivative, Nonmonetary Notional Amount, Energy Measure Derivative, Nonmonetary Notional Amount, Energy Measure Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan [Table] Accrual for environmental loss contingencies Accrual for Environmental Loss Contingencies Amortization — prior service credit, net Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Operating Segments Operating Segments [Member] Accrual for environmental loss contingencies, current Accrued Environmental Loss Contingencies, Current 2026 Term Loan Facility 2026 Term Loan Facility [Member] 2026 Term Loan Facility Non-cash restructuring and impairment charges Non-Cash Restructuring Costs and Asset Impairment Charges Non-Cash Restructuring Costs and Asset Impairment Charges 7. SHARE-BASED COMPENSATION Share-Based Payment Arrangement [Text Block] Other assets Increase (Decrease) in Other Operating Assets Stock issued during period (in shares) Stock Issued During Period, Shares, New Issues PEO PEO [Member] 2 years Long-Term Debt, Maturity, Year Two Total debt Debt, Long-Term and Short-Term, Combined Amount 5.875% Senior Notes due September 2026 5.875% Senior Notes due September 2026 [Member] 5.875% Senior Notes due September 2026 Total compensation expense Share-Based Payment Arrangement, Expense Realized losses on change in fair value of derivative instruments, net Gain Loss On Change In Fair Value Of Other Realized Derivative Instruments Net (Gain) loss on change in fair value of other realized derivative instruments, net. Consolidation [Abstract] Consolidation [Abstract] Consolidation Other long-term liabilities Other Liabilities, Noncurrent Goodwill Goodwill Retirement Plan Type [Axis] Retirement Plan Type [Axis] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Total cash flow hedging derivatives OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Subsequent Event Type [Domain] Subsequent Event Type [Domain] (Accumulated Deficit)/Retained Earnings Retained Earnings [Member] Revolving Credit Facility Revolving Credit Facility [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Currency Translation Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Foreign currency translation and other Restructuring Reserve, Translation and Other Adjustment Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Number of plants with recycling operations Number of Plants with Recycling Operations Number of plants with recycling operations Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Aluminum Norf GmbH Aluminum Norf GmbH [Member] Aluminum Norf GmbH [Member] Cash flow hedges Cash Flow Hedging [Member] Gain on unrealized derivatives and other realized derivatives in investing activities, net Unrealized Gain (Loss) on Investments Research and development expenses Research and Development Expense Adjustments to determine net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] 3 years Long-Term Debt, Maturity, Year Three Aerospace and industrial plate Aerospace Products [Member] Aerospace Products Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Share-Based Payment Arrangement [Abstract] FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property, plant and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Net sales Revenue from Contract with Customer, Excluding Assessed Tax Remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Interest cost Defined Benefit Plan, Interest Cost Fair value of derivative, asset Derivative Asset 3. INVENTORIES Inventory Disclosure [Text Block] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Comprehensive loss attributable to noncontrolling interests, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Principal payments of long-term and short-term borrowings Repayments of Debt and Lease Obligation Summary of the impact on AOCI and earnings of derivative instruments designated as cash flow hedges Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Cash Cash 10. FINANCIAL INSTRUMENTS AND COMMODITY CONTRACTS Financial Instruments Disclosure [Text Block] AluInfra Services SA AluInfra Services SA [Member] AluInfra Services SA [Member] Other Payment for (Proceeds from) Other Investing Activity Inventories Increase (Decrease) in Inventories Segment Reporting [Table] Segment Reporting [Table] Principal repayment requirements for total debt over the next five years and thereafter Schedule of Maturities of Long-Term Debt [Table Text Block] Excess costs to fulfill customer contracts Additional Freight Costs Additional Freight Costs Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Total loss (gain) recognized in other expenses (income), net Derivative, Gain (Loss) on Derivative, Net Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Adjusted EBITDA Operating Income (Loss) Fair value of effective portion of cash flow hedges, tax provision (benefit) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Current Fiscal Year End Date Current Fiscal Year End Date Proceeds from issuance of long-term and short-term borrowings Proceeds from Issuance of Debt SEC Schedule, 12-09, Reserve, Environmental Cost SEC Schedule, 12-09, Reserve, Environmental Cost [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Derivative [Line Items] Derivative [Line Items] Additional contributions Contributions To Equity Method Investee Contributions To Equity Method Investee Return of capital to our common shareholder Return of capital to our common shareholder Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service cost Defined Benefit Plan, Service Cost Revolving credit facilities and other, net Proceeds from (Repayments of) Short-Term Debt China Loan, due September 2027 China Loan, Due September 2027 [Member] China Loan, Due September 2027 Net change in fair value of effective portion of cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Restructuring costs Restructuring Costs Common stock, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] 5. INVESTMENT IN AND ADVANCES TO NON-CONSOLIDATED AFFILIATES AND RELATED PARTY TRANSACTIONS Equity Method Investments and Joint Ventures Disclosure [Text Block] Annual royalty payable as percent of consolidated net revenue Annual Royalty Payable As Percent Of Consolidated Net Revenue Annual Royalty Payable As Percent Of Consolidated Net Revenue Schedule of variable interest entity Schedule of Variable Interest Entities [Table Text Block] Finished goods Inventory, Finished Goods, Gross Forward Contracts [Member] Forward Contracts [Member] Structural Cost Improvement and Efficiency Structural Cost Improvement and Efficiency [Member] Structural Cost Improvement and Efficiency 11. ACCUMULATED OTHER COMPREHENSIVE LOSS Comprehensive Income (Loss) Note [Text Block] Cost of goods sold (exclusive of depreciation and amortization) Cost of goods sold (exclusive of depreciation and amortization) Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Equity Components [Axis] Equity Components [Axis] Equity Components [Axis] Midwest Premium ("MWP") Contracts Midwest Premium ("MWP") Contracts [Member] Midwest Premium ("MWP") Contracts Accounts receivable Increase (Decrease) in Accounts Receivable Product and Service [Domain] Product and Service [Domain] Related Party Related Party [Member] Valuation allowance Deferred Tax Assets, Valuation Allowance Entity Interactive Data Current Entity Interactive Data Current Supplies Other Inventory, Supplies, Gross Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Deferred income tax liabilities Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Contribution for Financing of Social Security, tax credit Contribution For Financing of Social Security, Tax Credit Contribution For Financing of Social Security, Tax Credit Comprehensive income attributable to our common shareholder Comprehensive Income (Loss), Net of Tax, Attributable to Parent Unamortized discount Debt Instrument, Unamortized Discount Termination Date Trading Arrangement Termination Date Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] 1. BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Business Description and Accounting Policies [Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Change in pension and other (benefit) provision, net of tax provision included in other comprehensive income (loss) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] September Oswego fire losses, net of recoveries Fire1 [Member] Fire1 Modification of debt Debt Instrument, Modification Amount Debt Instrument, Modification Amount Parties Other long-term assets Other long-term assets — related parties Other Assets, Noncurrent Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Document Type Document Type Losses, net of recoveries Gain (Loss) From Insurance Settlement Gain (Loss) From Insurance Settlement Foreign Currency [Abstract] Foreign Currency [Abstract] 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] Fair value of derivative instruments Derivative Assets, Current Derivative Asset, Current Loss on extinguishment of debt, net Gain on extinguishment of debt, net Gain (Loss) on Extinguishment of Debt Accrued expenses and other current liabilities Accrued Liabilities, Current Fair Value as of Grant Date Award Grant Date Fair Value Short Short [Member] Triggering Event [Axis] Triggering Event [Axis] Triggering Event BRAZIL BRAZIL Income before income tax provision Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Expected additional contribution to funded pension plan Additional Contributions To Funded Pension Plan Additional contributions to funded pension plan. Currency translation adjustment included in other comprehensive income Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Reversal of accrued costs Repairs And Clean-Up Costs, Reversal Of Accrued Costs Repairs And Clean-Up Costs, Reversal Of Accrued Costs Local Phone Number Local Phone Number Work in process Inventory, Work in Process, Gross Other Benefit Plans Other Benefit Plans Other Postretirement Benefits Plan [Member] Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Royalty payable Accrued Royalties Net investment hedges Net Investment Hedging [Member] Undiscounted Environmental Clean-Up Costs Undiscounted Environmental Clean-Up Costs [Member] Undiscounted Environmental Clean-Up Costs [Member] Bonds Bonds [Member] Other comprehensive income before income tax effect Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent China Revolver China Revolver [Member] China Revolver Income before income tax provision Income before income tax provision Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Number of countries Company operates in Number of Countries in which Entity Operates Series 2025 B Bonds, due June 2032 Series 2025 B Bonds, due June 2032 [Member] Series 2025 B Bonds, due June 2032 Commitments and contingencies Commitments and Contingencies Net sales Revenues Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Equity in net income of non-consolidated affiliates Equity in net income of non-consolidated affiliates Income (Loss) from Equity Method Investments Other long-term assets Other Assets [Abstract] ABL Revolver ABL Revolver [Member] ABL Revolver [Member] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Other, net Other Nonoperating Income (Expense), Nonsegment Other Nonoperating Income (Expense), Nonsegment Environmental Remediation Contingency [Axis] Environmental Remediation Contingency [Axis] Executive Category: Executive Category [Axis] China CHINA From 2015 to 2017 From 2015 to 2017 [Member] From 2015 to 2017 Senior Notes due April 2029 Senior Notes due April 2029 [Member] Senior Notes due April 2029 Counterparty Name [Axis] Counterparty Name [Axis] LIABILITIES AND SHAREHOLDER'S EQUITY Liabilities and Equity [Abstract] Derivative assets and liabilities measured and recognized at fair value on a recurring basis classified under the appropriate level of the fair value hierarchy Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Maximum amortization period of unfunded actuarial liability Unfunded Actuarial Liability, Maximum Amortization Period Unfunded Actuarial Liability, Maximum Amortization Period Supplier finance program, obligation Supplier Finance Program, Obligation Inventories Inventories Inventory, Net Equity Award [Domain] Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount 12. FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] Change in fair value of effective portion of cash flow hedges, net of tax provision (benefit) included in other comprehensive (loss) income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Supplemental Disclosures: Supplemental Cash Flow Information [Abstract] Contributions to employee benefit plans Defined Contribution Plan Disclosures [Table Text Block] Common Stock, Shares Authorized, Unlimited [Fixed List] Common Stock, Shares Authorized, Unlimited [Fixed List] PEO Name PEO Name Geographical [Axis] Geographical [Axis] Sierre Loan, due October 2027 Sierre Loan, due October 2027 [Member] Sierre Loan, due October 2027 Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Segment Reporting, Other Segment Item, Amount Segment Reporting, Other Segment Item, Amount Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Proceeds (outflows) from the settlement of derivative instruments, net Payments for (Proceeds from) Derivative Instrument, Investing Activities Cash payments Payments for Restructuring Metal price lag Impact Of Metal Price Lag Impact Of Metal Price Lag Cash, cash equivalents and restricted cash – beginning of period Cash, cash equivalents and restricted cash – end of period Cash, cash equivalents and restricted cash – end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Accounts payable Increase (Decrease) in Accounts Payable Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Fair Value, Measurement Frequency [Domain] Measurement Frequency [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Ownership percentage Equity Method Investment, Ownership Percentage Idle fixed costs Labor and Related Expense China Loan, due January 2029 China Loan, due January 2029 [Member] China Loan, due January 2029 Specialty Specialty And Other [Member] Specialty And Other [Member] Schedule of debt Schedule of Debt [Table Text Block] Investment, Name [Domain] Investment, Name [Domain] Schedule of inventories Schedule of Inventory, Current [Table Text Block] Short-term borrowings and current portion of long-term debt due within one year Long-Term Debt, Maturity, Year One Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Fair values of financial instruments and commodity contracts Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Raw materials Inventory, Raw Materials, Gross Logan Aluminum Inc. Logan Aluminum Inc. [Member] Logan Aluminum Inc. Total current assets Total current assets Assets, Current Range [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Derivative instruments, gain (loss) recognition Derivative Instruments, Gain (Loss) [Table Text Block] China Loan, due November 2027 China Loan, due November 2027 [Member] China Loan, due November 2027 Award Type [Axis] Award Type [Axis] Debt issuance costs Payments of Financing Costs Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Restructuring and Related Activities [Abstract] Restructuring and Related Activities [Abstract] Product and Service [Axis] Product and Service [Axis] Restricted cash (included in other long-term assets) Restricted Cash, Noncurrent Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Losses (gains) recognized on balance sheet remeasurement currency exchange contracts, net Unrealized Gains Losses On Balance Sheet Remeasurement Currency Exchange Contracts Net Unrealized gains (losses) on balance sheet remeasurement currency exchange contracts, net. Pension Benefit Plans Pension Benefit Plans Pension Plan [Member] Common Stock Common Stock [Member] Employees Employee Severance [Member] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] 6.375% Senior Notes due August 2033 6.375% Senior Notes due August 2033 [Member] 6.375% Senior Notes due August 2033 North America North America Segment [Member] North America Segment Derivative Contract [Domain] Derivative Contract [Domain] Equity Awards Adjustments Equity Awards Adjustments [Member] Hedging Relationship [Domain] Hedging Relationship [Domain] Asia And South America Asia And South America [Member] Asia And South America Number of continents Company operates in Number of Continents in which Entity Operates The number of continents in which the entity operates as of balance sheet date. Derivative Liabilities, Noncurrent Derivative Liability, Noncurrent Total liabilities and equity Liabilities and Equity 2. RESTRUCTURING AND IMPAIRMENT Restructuring, Impairment, and Other Activities Disclosure [Text Block] Employee Stock Option Share-Based Payment Arrangement, Option [Member] Losses (gains) recognized on balance sheet remeasurement currency exchange contracts, net Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments Noncontrolling interests Equity, Attributable to Noncontrolling Interest Segments [Axis] Segments [Axis] Other liabilities Increase (Decrease) in Other Operating Liabilities Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Transfers out of Level 2 Fair Value, Measurement With Inputs Reconciliation, Liability, Transfers Out Of Level 2 Fair Value, Measurement With Inputs Reconciliation, Liability, Transfers Out Of Level 2 Restructuring charges Expenses recognized Restructuring Charges Related Party [Domain] Related and Nonrelated Parties [Domain] Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] Tabular List, Table Tabular List [Table Text Block] Other expenses (income), net Other income Other Nonoperating Income (Expense) Name Awards Close in Time to MNPI Disclosures, Individual Name Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Sale of stock, price per share (in dollars per share) Sale of Stock, Price Per Share Outflows from investment in and advances to non-consolidated affiliates, net Payments for (Proceeds from) Investments In And Advances To Affiliate Payments for (Proceeds from) Investments In And Advances To Affiliate Ulsan Aluminum, Ltd. Ulsan Aluminum, Ltd. [Member] Ulsan Aluminum, Ltd. [Member] Adjustment to Compensation: Adjustment to Compensation [Axis] Amounts reclassified from accumulated other comprehensive loss, net Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Derivative, fixed interest rate Derivative, Average Fixed Interest Rate Automotive Automotive Products [Member] Automotive Products [Member] Hedging Designation [Domain] Hedging Designation [Domain] Potential additional borrowing capacity Line of Credit Facility, Increase In Borrowing Capacity Amount of potential additional borrowing capacity under the credit facility. Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Capital expenditures Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Total contributions Payment for Pension and Other Postretirement Benefits Extinguishment of debt Extinguishment of Debt, Amount Settlement and curtailment gain Pension curtailment and settlement gains Settlement and curtailment gain Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment Hedging Designation [Axis] Hedging Designation [Axis] Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Assets Assets, Fair Value Disclosure Long-term debt, net of current portion Long-term debt, net of current portion, Carrying Value Long-Term Debt and Lease Obligation Name Measure Name 14. INCOME TAXES Income Tax Disclosure [Text Block] Parties Accounts payable Accounts payable — related parties Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Other, net Other Noncash Income (Expense) Debt Instrument Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Richmond and Fairmont Plants Richmond and Fairmont Plants [Member] Richmond and Fairmont Plants Retirement Plan Type [Domain] Retirement Plan Type [Domain] Additional Paid-in Capital Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category 2023 Term Loans 2023 Term Loans [Member] 2023 Term Loans Europe Premium Duty Paid ("ECDP") Contracts Europe Premium Duty Paid ("ECDP") Contracts [Member] Europe Premium Duty Paid ("ECDP") Contracts Name Trading Arrangement, Individual Name Unrecognized compensation expense Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Cash and cash equivalents Cash and Cash Equivalent Position [Domain] Position [Domain] Realized gains on derivative instruments not included in Adjusted EBITDA(2) Realized Gain (Loss) on Derivative Instruments, Not Included in Segment Income Realized Gain (Loss) on Derivative Instruments, Not Included in Segment Income Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Company Selected Measure Amount Company Selected Measure Amount Senior Notes due November 2026 Senior Notes due November 2026 [Member] Senior Notes due November 2026 Reconciliation from income from reportable segments to "Net income attributable to out common shareholder" Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Table Text Block] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Senior Notes Due 2030 Senior Notes Due 2030 [Member] Senior Notes Due 2030 [Member] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization Funded pension plans Defined Contribution Plan Employers Contribution To Funded Pension Plan Defined contribution plan employers contribution to funded pension plan. Net income Net income Net income from continuing operations Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Leased assets obtained in exchange for new finance lease liabilities Right-of-Use Asset Obtained in Exchange for Finance Lease Liability 5 years Long-Term Debt, Maturity, Year Five Current assets: Assets, Current [Abstract] Sierre business interruption insurance recoveries Insurance Recoveries Fair value of derivative, liability Derivative Liability Derivative Liability Currency (gains) losses included in other income expense Currency Gains Losses Included In Other Income Expense [Abstract] Currency gains losses included in other income expense. Non-PEO NEO Non-PEO NEO [Member] Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Income tax provision Income tax provision (benefit) Income Tax Expense (Benefit) Currency losses, net Currency losses, net Gain (Loss), Foreign Currency Transaction, before Tax 13. OTHER EXPENSES (INCOME), NET Other Income and Other Expense Disclosure [Text Block] Floating rate Term Loans, due March 2032 Floating rate Term Loans, due March 2032 [Member] Floating rate Term Loans, due March 2032 Costs and expenses related to net sales Cost of Product and Service Sold Award Timing Method Award Timing Method [Text Block] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Derivative remaining maturity (in years) Derivative, Remaining Maturity Consolidation Policy Consolidation, Policy [Policy Text Block] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Savings and defined contribution pension plans Defined Contribution Plan Employers Contribution To Savings And Defined Contribution Pension Plan Defined contribution plan employers contribution to savings and defined contribution pension plan. Gross deferred tax assets Deferred Tax Assets, Gross Deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Amortization — losses (gains), net Defined Benefit Plan, Amortization of Gain (Loss) Net income attributable to our common shareholder Net income (loss) attributable to our common shareholder Net Income (Loss) Attributable to Parent Net sales – third party Sales Revenue, Third Party [Member] Sales Revenue, Third Party [Member] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Unamortized debt issuance cost Unamortized Debt Issuance Expense Unamortized Carrying Value Adjustments Debt Instrument, Unamortized Carrying Value Adjustment Unamortized carrying value adjustment of debt instrument (including both long-term debt and capital lease obligations). Balance Sheet Location [Axis] Location, Statement of Financial Position, Balance [Axis] Statement [Table] Statement [Table] Catastrophic Event [Axis] Catastrophic Event [Axis] Restatement Determination Date: Restatement Determination Date [Axis] Accumulated other comprehensive income, net of tax Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Unrealized (gains) losses on change in fair value of derivative instruments, net Unrealized Gains Losses On Other Derivative Instruments Net Unrealized gains (losses) on other derivative instruments, net. Net actuarial gains (losses), amortization periods Net Actuarial Gains (Losses), Amortization Periods Net Actuarial Gains (Losses), Amortization Periods Number of operating plants Number of Operating Plants Number of operating plants. Tariff and freight costs Tariff And Freight Costs Tariff And Freight Costs Currency (gains) losses included in Other (income) expense, net Currency (gains) losses included in Other (income) expense, net [Table Text Block] Currency (gains) losses included in Other (income) expense, net Loss on foreign exchange remeasurement of debt Unrealized Gain (Loss), Foreign Currency Transaction, before Tax Diesel Fuel Forward Contracts Diesel Fuel Forward Contracts [Member] Diesel Fuel Forward Contracts [Member] South America South America Segment [Member] South America Segment Amount of Gain (Loss) Recognized in  Other expenses (income), net  (Excluded Portion) Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]