Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Revision of Prior Period [Axis] Revision of Prior Period [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Accounts payable Accounts Payable [Member] Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Commodity Contract Commodity Contract [Member] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Award Timing Predetermined Award Timing Predetermined [Flag] Entity File Number Entity File Number Capital in Excess of Par Value of Shares Additional Paid-in Capital [Member] Tabular List, Table Tabular List [Table Text Block] Earnings Per Share, Basic [Abstract] Earnings Per Share, Basic [Abstract] SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION Additional Financial Information Disclosure [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Defined benefit pension contributions Payment for Pension Benefits Other Other [Member] Other [Member] Type of Restructuring [Domain] Type of Restructuring [Domain] Interest expense, net Interest Income (Expense), Nonoperating Surety-backed letters of credit and surety bonds outstanding Guarantor Obligations, Maximum Exposure, Undiscounted Employee stock plan Share-Based Payment Arrangement [Member] Goodwill [Line Items] Goodwill [Line Items] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Measurement Basis [Axis] Measurement Basis [Axis] Earnings Per Share, Basic, Total Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Payables, accrued employment and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Remediation payments Asset Retirement Obligation, Liabilities Settled REVENUES Revenue from Contract with Customer [Text Block] Shareholders' Equity [Table] Stock, Class of Stock [Table] Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Schedule Of Segment Reporting Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Asset retirement and environmental obligations Asset retirement and environmental obligations Asset retirement and environmental obligations DERIVATIVE INSTRUMENTS AND HEDGING Derivatives and Fair Value [Text Block] Pension and OPEB payments and contributions Payment for Pension and Other Postretirement Benefits Defined Benefit Plan, Other Cost (Credit) Defined Benefit Plan, Other Cost (Credit) Revision in estimated cash flows Asset Retirement Obligation, Revision of Estimate Adjustment to Compensation, Amount Adjustment to Compensation Amount Pension Plan Pension Plan [Member] Unamortized discounts and issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Basis of Consolidation Consolidation, Policy [Policy Text Block] Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Cleveland-Cliffs Inc. Cleveland-Cliffs Inc. [Member] Cleveland-Cliffs Inc. [Member] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Income taxes paid Income Taxes Paid Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Asset Impairment Charges Asset impairment Asset Impairment Charges Total Cliffs shareholders' equity Equity, Attributable to Parent Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] Value Of Each Of The Major Classes Of Consolidated Depreciable Assets Property, Plant and Equipment [Table Text Block] Common shares, authorized (in shares) Common Stock, Shares Authorized Segment Reporting, Asset Reconciling Item [Line Items] Segment Reporting, Asset Reconciling Item [Line Items] Surety Bond Surety Bond [Member] Direct automotive Automotive [Member] Automotive [Member] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Current assets: Assets, Current [Abstract] TOTAL LIABILITIES AND EQUITY Liabilities and Equity Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Accumulated Defined Benefit Plans Adjustment Attributable to Parent Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Adj EBITDA Calculation [Domain] Adj EBITDA Calculation [Domain] Adj EBITDA Calculation [Domain] Cover [Abstract] Cover [Abstract] Net losses (gains) reclassified from AOCI to net income Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Performance period Share-Based Compensation Arrangement by Share-Based Payment Award, Performance Period Share-Based Compensation Arrangement by Share-Based Payment Award, Performance Period Maximum Maximum [Member] Distributors and converters Distributors and converters [Member] Distributors and converters Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net Income (Loss) Attributable to Noncontrolling Interest Capital additions Segment, Expenditure, Addition to Long-Lived Assets Finite-Lived Intangible Assets, Net, Total Finite-Lived Intangible Assets, Net Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Net periodic benefit credits other than service cost component Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Common Shares in Treasury Treasury Stock, Common [Member] Loss from continuing operations Loss from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Series B Preferred Stock Series B Preferred Stock [Member] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount LIABILITIES AND EQUITY Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Loss from continuing operations before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Schedule of Carrying Value and Fair Value Of Financial Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Other non-current liabilities Other Liabilities, Noncurrent Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Other Adjustments, Net Other Adjustments, Net Other Adjustments, Net Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Segments Operating Segments [Member] Above-market supply contracts, Net Finite-Lived Intangible Liability, Net Finite-Lived Intangible Liability, Net Coated steel Coated steel [Member] Coated steel Schedule of Supplemental Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Variable Interest Entity [Table] Variable Interest Entity [Table] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Cash and cash equivalents at end of period Cash Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Line of Credit Facility [Table] Line of Credit Facility [Table] Comprehensive loss attributable to Cliffs shareholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Name Measure Name Loss from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Restructuring Reserve, Beginning Balance Restructuring Reserve, Ending Balance Restructuring Reserve Letter of Credit Letter of Credit [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Class of Stock [Line Items] Class of Stock [Line Items] Industry Sector [Domain] Industry Sector [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Loss from discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Award Timing Method Award Timing Method [Text Block] Continuing operations Income (Loss) from Continuing Operations, Per Basic Share Reclassification of net losses Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Award Type Award Type [Axis] Accumulated Foreign Currency Adjustment Attributable to Parent Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Revision of Prior Period, Adjustment Revision of Prior Period, Adjustment [Member] Long-term Debt Long-Term Debt Legal Entity [Axis] Legal Entity [Axis] TOTAL ASSETS Total assets Assets 2027 Finite-Lived Intangible Asset, Expected Amortization, Year One Trading Symbol Trading Symbol Schedule of Intangible Assets and Liabilities Schedule of Intangible Assets and Goodwill [Table Text Block] Stock and other incentive plans (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Environmental Remediation Obligations [Abstract] Entity Address, City or Town Entity Address, City or Town OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Segment Reporting, Other Segment Item, Amount Segment Reporting, Other Segment Item, Amount Effect of exchange rate changes on cash Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Asset Retirement Obligation [Roll Forward] Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Statement of Income Location, Balance [Domain] Statement of Income Location, Balance [Domain] Severance Costs Severance Costs Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Capital additions Property, Plant and Equipment, Additions Amortization of inventory step-up [Abstract] Amortization of inventory step-up Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] 2030 Finite-Lived Intangible Asset, Expected Amortization, Year Four Restructuring and other charges Restructuring Costs Entity Emerging Growth Company Entity Emerging Growth Company 2028 Long-Term Debt, Maturity, Year Three Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding 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] Level 2 Fair Value, Inputs, Level 2 [Member] Grant-date stock price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Payments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Common shares, outstanding (in shares) Balance, beginning of period (in shares) Balance, end of period (in shares) Common Stock, Shares, Outstanding Gain (Loss) on Disposition of Other Assets Gain (Loss) on Disposition of Other Assets 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] PEO PEO [Member] Revenues by Market and Product Line Disaggregation of Revenue [Table Text Block] Land, land improvements and mineral rights Land, land improvements and mineral rights [Member] Land, land improvements and mineral rights [Member] Employee Severance Employee Severance [Member] Proceeds from issuance of senior notes Proceeds from Issuance of Senior Long-Term Debt Pension and OPEB assets Assets for Plan Benefits, Defined Benefit Plan Number of employees Entity Number of Employees Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [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] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Retained Earnings (Deficit) Retained Earnings [Member] HRC HRC [Member] HRC Discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Annual Effective Interest Rate Debt Instrument, Interest Rate, Effective Percentage 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contracts, Gross Amount Finite-Lived Intangible Liability, Gross Finite-Lived Intangible Liability, Gross Total property, plant and equipment Property, Plant and Equipment, Gross Continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Net loss Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] City Area Code City Area Code Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Capitalized interest Interest Costs Capitalized Accrued expenses Accrued Liabilities, Current Remainder of 2025 Finite-Lived Intangible Liabilities, Amortization Credit, Remainder Of Fiscal Year Finite-Lived Intangible Liabilities, Amortization Credit, Remainder Of Fiscal Year Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash used by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Net actuarial loss (gain) Defined Benefit Plan, Amortization of Gain (Loss) Losses (gains) reclassified from AOCI to Cost of goods sold Cost of Sales [Member] Goodwill Beginning balance January 1, 2026 Ending balance June 30, 2026 Goodwill Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Depreciation and depletion expense Depreciation Environmental Exit Cost [Table] Environmental Exit Cost [Table] Remainder of 2026 Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Amortization of Intangible Liabilities Amortization Of Intangible Liability Amortization Of Intangible Liability Eliminations Eliminations [Member] Eliminations Equity Components [Axis] Equity Components [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Equipment Equipment [Member] Number of reportable segments Number of Reportable Segments Losses (gains) reclassified from AOCI to Revenues Sales [Member] Beginning balance as of January 1 Ending balance as of June 30 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] VARIABLE INTEREST ENTITIES Variable Interest Entity Disclosure [Text Block] Other Performance Measure, Amount Other Performance Measure, Amount Debt issuance costs Payments of Debt Issuance Costs Entity Address, State or Province Entity Address, State or Province Above-market supply contracts, Accumulated Amortization Finite-Lived Intangible Liability, Accumulated Amortization Finite-Lived Intangible Liability, Accumulated Amortization Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] Supplier Finance Program [Line Items] Supplier Finance Program [Line Items] Total current liabilities Liabilities, Current Other current liabilities Other Current Liabilities [Member] Net increase in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation Income tax refunds Proceeds from Income Tax Refunds Derivative Instrument [Axis] Derivative Instrument [Axis] Individual: Individual [Axis] Restricted cash Restricted Cash Summary of Asset Retirement Obligations Schedule of Asset Retirement Obligations [Table Text Block] Right-of-use assets - finance leases Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Other current assets Other Assets, Current Entity [Domain] Entity [Domain] Other Restructuring Other Restructuring [Member] Investment in affiliates Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Net cash used by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation 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] Derivative asset Derivative Asset, Noncurrent Interest paid on debt obligations net of capitalized interest Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Entity Interactive Data Current Entity Interactive Data Current 6.750% 2030 Senior Notes 6.750% 2030 Senior Notes [Member] 6.750% 2030 Senior Notes Deferred income taxes Deferred Tax and Other Liabilities, Noncurrent Carrying Value Reported Value Measurement [Member] Equity [Abstract] Equity [Abstract] Buildings Building [Member] SEGMENT REPORTING Segment Reporting Disclosure [Text Block] Goodwill [Table] Goodwill [Table] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Other Commitments [Line Items] Other Commitments [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Other Other Capitalized Property Plant and Equipment [Member] Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Pension and OPEB credits Pension and Other Postretirement Benefits Expense (Reversal of Expense), Noncash Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] ACCUMULATED OTHER COMPREHENSIVE INCOME Comprehensive Income (Loss) Note [Text Block] Amortization of Intangible Assets Amortization of Intangible Assets Total product inventories Inventory, Finished Goods and Work in Process, Net of Reserves Selling, general and administrative expenses Selling, General and Administrative Expense Selling, General and Administrative Expense Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Depreciation, depletion and amortization Depreciation, depletion and amortization Depreciation, Depletion and Amortization Foreign currency translation Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Foreign Currency Translation Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Foreign Currency Translation Other non-current assets Other Assets, Noncurrent Customer [Domain] Customer [Domain] Entity Central Index Key Entity Central Index Key PEO Name PEO Name Asset retirement obligations Asset retirement obligation at beginning of period Asset retirement obligation at end of period Asset Retirement Obligation Schedule of Maturities of Long-term Debt Schedule of Maturities of Long-Term Debt [Table Text Block] Revenues Revenues Error Correction [Table] Error Correction [Table] Changes in fair value of derivatives, net Changes in fair value of derivatives, net Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net 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] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount ABL Facility Revolving Credit Facility [Member] Beginning balance as of January 1 Ending balance as of June 30 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Hot-rolled steel Hot-rolled steel [Member] Hot-rolled steel Segments [Axis] Segments [Axis] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Exercise Price Award Exercise Price Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Entity Filer Category Entity Filer Category Class of Stock [Domain] Class of Stock [Domain] Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Other investing activities Payment for (Proceeds from) Other Investing Activity Thereafter Long-Term Debt, Maturity, after Year Five STOCK COMPENSATION PLANS Share-Based Payment Arrangement [Text Block] ASSETS Assets [Abstract] Long-term debt Long-Term Debt, Excluding Current Maturities Underlying Security Market Price Change Underlying Security Market Price Change, Percent 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Three Statement of Financial Position Location, Balance [Axis] Statement of Financial Position Location, Balance [Axis] Debt Instrument [Axis] Debt Instrument [Axis] FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] PENSIONS AND OTHER POSTRETIREMENT BENEFITS Retirement Benefits [Text Block] Finite-Lived Intangible Assets, Gross Finite-Lived Intangible Assets, Gross SHAREHOLDERS' EQUITY Equity, Attributable to Parent [Abstract] Derivative Liability, Current Derivative Liability, Current 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] Payout range Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage Entity Address, Address Line One Entity Address, Address Line One AOCI Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Prior service credits Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Industry Sector [Axis] Industry Sector [Axis] 4.875% 2031 Senior Notes 4.875% 2031 Senior Notes [Member] 4.875% 2031 Senior Notes Restructuring, Settlement and Impairment Provisions Restructuring, Settlement and Impairment Provisions Fair Value as of Grant Date Award Grant Date Fair Value Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Entity Registrant Name Entity Registrant Name Other Businesses Other Businesses [Member] Other Businesses Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Net periodic benefit costs (credits) Net periodic benefit costs (credits) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Schedule of Long-Term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Employee stock plans (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Total operating costs Costs and Expenses Income taxes Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable Document Quarterly Report Document Quarterly Report Total Long-Term Debt, Fair Value Revision of Prior Period [Domain] Revision of Prior Period [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Other assets (liabilities), net Other Assets (Liabilities), Net Other Assets (Liabilities), Net Energy [Axis] Energy [Axis] Finance Lease, Right-of-Use Asset, before Accumulated Amortization Finance Lease, Right-of-Use Asset, before Accumulated Amortization Number of operating segments Number of Operating Segments Equipment financed with seller Property, Plant, And Equipment, Financed Purchase Property, Plant, And Equipment, Financed Purchase Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Interest cost Defined Benefit Plan, Interest Cost Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Restatement Determination Date: Restatement Determination Date [Axis] Supplier Finance Program [Table] Supplier Finance Program [Table] Stock and other incentive plans Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Non-PEO NEO Non-PEO NEO [Member] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Less: current portion Asset Retirement Obligation, Current Other financing activities Proceeds from (Payment for) Other Financing Activity Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Name Trading Arrangement, Individual Name All Award Types Award Type [Domain] Noncontrolling interests Noncontrolling interests Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Other Other Noncash Income (Expense) 4.625% 2029 Senior Notes 4.625% 2029 Senior Notes [Member] 4.625% 2029 Senior Notes Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Compensation Amount Outstanding Recovery Compensation Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Retirement Plan Type [Domain] Retirement Plan Type [Domain] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Energy [Domain] Energy [Domain] Payments for Restructuring Payments for Restructuring 2029 Finite-Lived Intangible Liabilities, Amortization Credit, Year Four Finite-Lived Intangible Liabilities, Amortization Credit, Year Four Restructuring Type [Axis] Restructuring Type [Axis] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Cash-Settled Sales Swaps Cash-Settled Sales Swaps [Member] Cash-Settled Sales Swaps Stock and other incentive plans APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax 2026 Long-Term Debt, Maturity, Year One Income tax Other Comprehensive Income (Loss) before Reclassifications, Tax Supplier relationships Supplier Relationships [Member] Supplier Relationships Liability Class [Axis] Liability Class [Axis] Segments [Domain] Segments [Domain] Statement of Income Location, Balance [Axis] Statement of Income Location, Balance [Axis] 2030 Long-Term Debt, Maturity, Year Five Borrowing capacity available Line of Credit Facility, Remaining Borrowing Capacity Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Postemployment Benefits [Abstract] Postemployment Benefits [Abstract] Changes in derivative instruments, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Statement of Financial Position Location, Balance [Domain] Statement of Financial Position Location, Balance [Domain] Inventories Increase (Decrease) in Inventories Adjusted EBITDA Adjusted EBITDA, Earnings (Loss) Adjusted EBITDA, Earnings (Loss) Inventories Inventories Inventory, Net Accrued Environmental Loss Contingencies, Current Accrued Environmental Loss Contingencies, Current Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Minimum Minimum [Member] Non-current assets: Assets, Noncurrent [Abstract] Allowance for depreciation and depletion Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accretion expense Asset Retirement Obligation, Accretion Expense Company Selected Measure Name Company Selected Measure Name Accrual for Environmental Loss Contingencies Accrual for Environmental Loss Contingencies Fair Value Measurement [Domain] Fair 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Contingencies Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Reconciliation of Assets from Segment to Consolidated [Table] Reconciliation of Assets from Segment to Consolidated [Table] Natural Gas Natural Gas and Natural Gas Liquids (NGL) [Member] Comprehensive loss Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Entity Small Business Entity Small Business Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Non-Controlling Interest Noncontrolling Interest [Member] Steelmaking Steelmaking [Member] Steelmaking [Member] Preferred stock outstanding (in shares) Preferred Stock, Shares Outstanding Document Transition Report Document Transition Report Investment in Affiliates Equity Method Investments [Policy Text Block] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] 7.375% 2033 Senior Notes [Member] 7.375% 2033 Senior Notes [Member] 7.375% 2033 Senior Notes Underlying Securities Award Underlying Securities Amount Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, before Tax Equity Component [Domain] Equity Component [Domain] Adj EBITDA Calculation Adj EBITDA Calculation [Member] Adj EBITDA Calculation Document Period End Date Document Period End Date 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] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount INCOME TAXES Income Tax Disclosure [Text Block] Loss per common share attributable to Cliffs shareholders - diluted Earnings Per Share, Diluted [Abstract] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Revenue from Contract with Customer [Abstract] EBITDA of noncontrolling interests EBITDA Of Noncontrolling Interests EBITDA Of Noncontrolling Interests Equity, Including Portion Attributable to Noncontrolling Interest, Total Balance, beginning of period Balance, end of period Equity, Including Portion Attributable to Noncontrolling Interest Other steel products Other steel products [Member] Other steel products Accounts receivable, net Increase (Decrease) in Accounts Receivable and Other Operating Assets Market Stock Units Market Stock Units [Member] Market Stock Units Document Type Document Type 7.625% 2034 Senior Notes [Member] 7.625% 2034 Senior Notes [Member] 7.625% 2034 Senior Notes Reconciliation of Assets from Segment to Consolidated Reconciliation of Assets from Segment to Consolidated [Table Text Block] EARNINGS PER SHARE Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Commitments Commitments [Member] Changes in pension and OPEB, net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Capital in excess of par value of shares Additional Paid in Capital Product and Service [Axis] Product and Service [Axis] Derivative Contract [Domain] Derivative Contract [Domain] All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Purchase of property, plant and equipment Cash paid for capital expenditures including deposits Payments to Acquire Property, Plant, and Equipment Name Forgone Recovery, Individual Name Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] 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] Manufacturing supplies and critical spares Inventory, Supplies, Net of Reserves Authorized amount of stock repurchase Share Repurchase Program, Authorized, Amount Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Foreign currency translation Goodwill, Foreign Currency Translation, Gain (Loss) Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Net loss attributable to Cliffs shareholders Net Income (Loss) Available to Common Stockholders, Basic Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Current liabilities: Liabilities, Current [Abstract] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Other, net Increase (Decrease) in Other Operating 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Basis, Unobservable Input Reconciliation [Line Items] Accrued Environmental Loss Contingencies, Noncurrent Accrued Environmental Loss Contingencies, Noncurrent Infrastructure and manufacturing Infrastructure and manufacturing [Member] Infrastructure and manufacturing Common shares in treasury (in shares) Treasury Stock, Common, Shares Loss per common share attributable to Cliffs shareholders - basic Earnings Per Share [Abstract] Restructuring Plan [Axis] Restructuring Plan [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Total other expense Nonoperating Income (Expense) Adj EBITDA Calculation [Axis] Adj EBITDA Calculation [Axis] Adj EBITDA Calculation Plate steel Plate steel [Member] Plate steel Total expense included in earnings Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings 6.875% 2029 Senior Notes [Member] 6.875% 2029 Senior Notes [Member] 6.875% 2029 Senior Notes 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Two Award Timing Disclosures [Line Items] Schedule of Change in Asset Retirement Obligation Schedule of Change in Asset Retirement Obligation [Table Text Block] Schedule of Inventory Schedule of Inventory, Current [Table Text Block] Service cost Defined Benefit Plan, Service Cost Long-term Debt, Gross Total maturities of debt Long-Term Debt, Gross Accrued employment costs Employee-related Liabilities, Current PROPERTY, PLANT AND EQUIPMENT Property, Plant and Equipment Disclosure [Text Block] Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Other Comprehensive Income (Loss), before Reclassifications, Net of Tax CAPITAL STOCK Equity [Text Block] Noncontrolling Interest, Other Increase Of Noncontrolling Interest Noncontrolling Interest, Other Increase Of Noncontrolling Interest Noncontrolling Interest, Other Increase Of Noncontrolling Interest Foreign currency translation Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Foreign Currency Translation Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Foreign Currency Translation Available borrowing base on ABL Facility Line of Credit Facility, Current Borrowing Capacity Net distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Net loss Net Income (Loss) Attributable to Parent Expiration Date Trading Arrangement Expiration Date Non-current liabilities: Liabilities, Noncurrent [Abstract] Stainless and electrical steel Stainless and electrical steel [Member] Stainless and electrical steel Construction in progress Construction in Progress [Member] 2031 Finite-Lived Intangible Asset, Expected Amortization, Year Five Discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Property, plant and equipment, net Property, plant and equipment, net Property, Plant and Equipment, Net Preferred stock authorized (in shares) Preferred Stock, Shares Authorized Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Restructuring and other charges Restructuring Charges Adoption Date Trading Arrangement Adoption Date Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] 6.250% 2040 Senior Notes 6.250% 2040 Senior Notes [Member] 6.250% 2040 Senior Notes [Member] Restructuring Cost [Table] Restructuring Cost [Table] Series A Preferred Stock Series A Preferred Stock [Member] Commodity Option Commodity Option [Member] Entity Current Reporting Status Entity Current Reporting Status Customer [Axis] Customer [Axis] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Customer relationships Customer Relationships [Member] Operating loss Operating Income (Loss) Consolidated Entities [Domain] Consolidated Entities [Domain] Line of Credit Line of Credit [Member] Retained deficit Retained Earnings (Accumulated Deficit) Third Party Third Party [Member] Third Party Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] 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] Executive Category: Executive Category [Axis] Long-term asset retirement obligations Asset Retirement Obligations, Noncurrent Miscellaneous – net Other Operating Income (Expense), Net Class of Stock [Axis] Class of Stock [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Developed technology Technology-Based Intangible Assets [Member] Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] 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] OPEB contributions Payment for Other Postretirement Benefits Retirement Plan Type [Axis] Retirement Plan Type [Axis] Statement [Table] Statement [Table] Other non-operating income Other Nonoperating Income (Expense) Deferred income taxes Deferred Income Tax Expense (Benefit) Adjustments to reconcile net loss to net cash used by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Schedule of Environmental Obligations Schedule of Environmental Loss Contingencies by Site [Table Text Block] Mining permits Mining Permits [Member] Mining Permits [Member] Antidilutive securities (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Weighted average number of shares: Weighted Average Number of Shares Outstanding, Diluted [Abstract] All Adjustments to Compensation All Adjustments to Compensation [Member] Electricity Electricity [Member] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Amendment Flag Amendment Flag 2027 Long-Term Debt, Maturity, Year Two Defined benefit plan Other Postretirement Benefits Plan [Member] Cost of 35,523,974 common shares in treasury (2025 - 36,292,287 shares) Treasury Stock, Common, Value Other Commitments [Table] Other Commitments [Table] Termination Date Trading Arrangement Termination Date Environmental Exit Cost [Line Items] Environmental Exit Cost [Line Items] Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Raw materials Inventory, Raw Materials, Net of Reserves BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Significant Accounting Policies [Text Block] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Remaining authorized amount of stock repurchase Share Repurchase Program, Remaining Authorized, Amount Cost of goods sold Cost of Product and Service Sold Cost of Product and Service Sold Cost of Product and Service Sold Earnings Per Share Computation Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Asset Retirement Obligation [Abstract] Asset Retirement Obligation [Abstract] Notional Amount Derivative, Nonmonetary Notional Amount 7.500% 2031 Senior Notes [Member] 7.500% 2031 Senior Notes [Member] 7.500% 2031 Senior Notes Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Other income (expense): Nonoperating Income (Expense) [Abstract] Entity Tax Identification Number Entity Tax Identification Number Operating costs: Costs and Expenses [Abstract] Income tax expense (benefit) Reclassification from AOCI, Current Period, Tax (Gains) losses reclassified from AOCI to net income Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Borrowings (repayments) under ABL Facility, net Proceeds from (Repayments of) Lines of Credit SunCoke Middletown SunCoke Middletown [Member] SunCoke Middletown [Member] 2028 Finite-Lived Intangible Liabilities, Amortization Credit, Year Three Finite-Lived Intangible Liabilities, Amortization Credit, Year Three Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Consolidated Entities [Axis] Consolidated Entities [Axis] Derivative Instrument, Percentage Of Interest In Commodity Option Derivative Instrument, Percentage Of Interest In Commodity Option Derivative Instrument, Percentage Of Interest In Commodity Option Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common shares, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common shares, issued (in shares) Common Stock, Shares, Issued Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] 2029 Long-Term Debt, Maturity, Year Four Steel producers Steel Producers [Member] Steel Producers [Member] 2026 Finite-Lived Intangible Liabilities, Amortization Credit, Year One Finite-Lived Intangible Liabilities, Amortization Credit, Year One Grants in period (in shars) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross GOODWILL AND INTANGIBLE ASSETS AND LIABILITIES Goodwill and Intangible Assets Disclosure [Text Block] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Schedule of Goodwill Schedule of Goodwill [Table Text Block] Trading Arrangement: Trading Arrangement [Axis] Derivative Asset, Current Derivative Asset, Current Total Shareholder Return Amount Total Shareholder Return Amount Total expense included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings 2030 Finite-Lived Intangible Liabilities, Amortization Credit, Year Five Finite-Lived Intangible Liabilities, Amortization Credit, Year Five SUBSEQUENT EVENTS Subsequent Events [Text Block] Changes in foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name TOTAL LIABILITIES Liabilities Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] 2027 Finite-Lived Intangible Liabilities, Amortization Credit, Year Two Finite-Lived Intangible Liabilities, Amortization Credit, Year Two Non-cash accruals Capital Expenditures Incurred but Not yet Paid Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Common shares - par value $0.125 per share Common Stock, Value, Outstanding Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Supplier financings Supplier Finance Program, Obligation, Current Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Other current liabilities Other Liabilities, Current Trade names and trademarks Trademarks and Trade Names [Member] Pension and OPEB liabilities Liability, Defined Benefit Plan, Noncurrent Depreciation, depletion and amortization attributable to noncontrolling interests Depreciation, Depletion And Amortization Attributable To Noncontrolling Interests Depreciation, Depletion And Amortization Attributable To Noncontrolling Interests Statement [Line Items] Statement [Line Items] Consolidation Items [Axis] Consolidation Items [Axis] Schedule of Restructuring Reserve by Type of Cost Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] 7.000% 2032 Senior Notes 7.000% 2032 Senior Notes [Member] 7.000% 2032 Senior Notes Cash and cash equivalents Cash and Cash Equivalent Common Stock Common Stock [Member] Cold-rolled steel Cold-rolled steel [Member] Cold-rolled steel Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member]