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Scenario [Axis] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Subsequent Events [Text Block] Subsequent Events Total debt Long-Term Debt APIC, Share-based Payment Arrangement, Increase for Cost Recognition, Total Stock-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Non cash gain (loss) Beginning balance Ending balance Equity, Attributable to Parent Total Shareholders' Equity Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Additional contributions expected to be made during remainder of fiscal year Interest Income and Interest Expense Disclosure [Table Text Block] Schedule of Interest (income) Expense Proceeds from Income Tax Refund, State and Local State and local income tax refunds Statement of Stockholders' Equity [Abstract] TimkenSteel corporation retirement plan. TimkenSteel Corporation Retirement Plan [Member] Salaried Plan Treasury Shares Treasury Stock, Common [Member] UNITED STATES United States of America Pension and Postretirement Liability Adjustments Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Debt Instrument, Name Debt Instrument, Name [Domain] Other current assets Other Assets, Current Special Bar Quality Bars [Member] Bar Special Bar Quality Bars [Member] Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] Credit Facility Credit Facility [Axis] Cost of Goods and Services Sold, Total Cost of products sold Cost of Product and Service Sold Debt Instrument, Repaid, Principal Company repaid principal amount Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Treasury Stock, Value, Total Treasury Stock, Value Treasury shares - 2026 - 6.5 million; 2025 - 6.5 million Government Assistance [Table] Foreign Tax Jurisdiction [Member] Foreign Pension Pension Plan [Member] Entity Address, City or Town Entity Address, City or Town Number of Reportable Segments Number of reportable segments Security Exchange Name Security Exchange Name Credit Facility Credit Facility [Domain] Income (Loss) Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] Antidilutive Securities, Name Antidilutive Securities, Name [Domain] Retirement Plan Sponsor Location [Axis] TimkenSteel U.K. pension scheme. TimkenSteel U.K. Pension Scheme [Member] Pension Scheme Total inventories, net Inventories, net Inventory, Net Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Cash, cash equivalents, and restricted cash at beginning of period Cash, Cash Equivalents, and Restricted Cash at End of Period Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows Total Current Assets Assets, Current Stock-based compensation expense Share-Based Payment Arrangement, Expense Document Period End Date Document Period End Date Other Income and Expenses [Abstract] Government Assistance, Liability, Current Government funding liabilities Industrial Industrial Market Sector [Member] Industrial Market Sector [Member] Statement of Financial Position [Abstract] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Automotive [Member] Automotive [Member] Automotive Incremental Common Shares Attributable To Share Based Payment Arrangements Shares Assumed Issued Incremental common Shares attributable to share based payment arrangements shares assumed Issued. Shares assumed issued Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive income (loss), net of benefit (provision) for income taxes of none and $(0.1) million for the three months ended March 31, 2026 and 2025. Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] 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] Total Liabilities Liabilities Other (Income) Expense, Net Other Nonoperating Income and Expense [Text Block] Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Amounts reclassified from accumulated other comprehensive income (loss), before income tax Pension Cost and Other Postretirement Benefits Cost (Reversal of Cost), Remeasurement Pension Cost and Other Postretirement Benefits Cost Reversal of Cost Remeasurement Total gain from remeasurement of benefit plans Total loss from remeasurement of benefit plans Loss (gain) from remeasurement of benefit plans New Accounting Pronouncement or Change in Accounting Principle, Description New accounting pronouncement description Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Restricted Cash Restricted Cash Weighted average shares outstanding, diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Government Assistance [Text Block] Government Funding Entity File Number Securities Act File Number Domestic Plan [Member] Domestic Plan Cover [Abstract] Deferred charges and prepaid expenses Prepaid Expense and Other Assets, Current Scenario [Domain] Liability, Defined Benefit Pension Plan, Noncurrent Pension Liability Number of Operating Segments Number of operating segments Segment Reporting Disclosure [Text Block] Segment Reporting Defined benefit plan term of contract. Defined Benefit Plan Term Of Contract Defined benefit plan term of contract Subsequent Event [Table] Gain (Loss) on Extinguishment of Debt, Total Gain (Loss) on Extinguishment of Debt Loss on extinguishment of debt Loss on extinguishment of debt Restructuring Charges, Total Expenses Restructuring charges Restructuring Charges Adoption of New Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Energy Energy Market Sector [Member] Energy Market Sector [Member] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Gain (Loss) on Disposition of Assets, Total Loss (gain) on sale or disposal of assets, net Gain (Loss) on Disposition of Assets Loss (gain) on sale or disposal of assets, net Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Curtailment losses (gains) Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Purchase of treasury shares, including excise tax (in Shares) Treasury stock, share, acquired. Treasury Stock, Share, Acquired Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax, Total Pension and postretirement liability adjustments Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Common Stock, Shares, Outstanding, Beginning Balance Common Stock, Shares, Outstanding, Ending Balance Common Stock, Shares, Outstanding Common Stock, Shares outstanding Current operating lease liabilities Operating Lease, Liability, Current Depreciation, Depletion and Amortization, Total Depreciation and amortization Depreciation, Depletion and Amortization Government assistance capital fundings. Government Assistance Capital Fundings Government assistance capital fundings Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Document Transition Report Document Transition Report Payments for Repurchase of Common Stock Purchase of treasury shares Purchase of treasury shares Schedule of (Benefit) Provision for Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Liability, Defined Benefit Plan, Noncurrent, Total Accrued pension and postretirement costs Liability, Defined Benefit Plan, Noncurrent Statement of Cash Flows [Abstract] Earnings (Loss) Per Share Earnings Per Share [Text Block] Net Income (Loss) Government Assistance [Line Items] Increase (Decrease) in Inventories, Total Inventories, net Increase (Decrease) in Inventories Payment for Pension and Other Postretirement Benefits, Total Pension and postretirement contributions and payments Payment for Pension and Other Postretirement Benefits Kristine C. Syrvalin Trading Arrangement Common Sale [Member] Kristine C. Syrvalin Trading Arrangement Common Sale. 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Other Liabilities, Noncurrent, Total Other non-current liabilities Other Liabilities, Noncurrent Finance Lease, Right-of-Use Asset, after Accumulated Amortization Finance Lease, Right-of-Use Asset, after Accumulated Amortization, Total Finance lease right-of-use assets 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] Income Tax Disclosure [Abstract] Additional Paid-in Capital Additional Paid-in Capital [Member] Investment Losses On Plan Assets Investment Losses On Plan Assets Investment losses on plan assets UNITED KINGDOM United Kingdom Defined benefit plan contract expiration date. Defined Benefit Plan Contract Expiration Date Defined benefit plan contract expiration date Share Repurchase Program, Authorized, Amount Stock Repurchase Program, Amount New Accounting Pronouncements Or Change In Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Trading Symbol Trading Symbol Subsequent Event Type [Axis] Subsequent Event Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Salaries, wages and benefits Salaries Wages And Benefits Current Salaries wages and benefits current. Number of Bargaining Employees Number of bargaining employees. Number of bargaining employees in the contract Increase Decreas in the Liability of Increase in the Discount Rate Increase decreas in the liability of increase in the discount rate. Offset amount in the decrease of liability Equity Components Equity Components [Axis] Equity Component Equity Component [Domain] Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement, Total Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement Settlements Defined benefit plan settlement Mobile Mobile Market Sector [Member] Mobile Market Sector [Member] Customer Customer [Axis] Statement of Comprehensive Income [Abstract] Seamless Mechanical Tubing [Member] Tube Seamless Mechanical Tubing [Member] Common Stock, Value, Issued, Ending Balance Common Stock, Value, Issued, Beginning Balance Common Stock, Value, Issued, Total Common Stock, Value, Issued Common shares, without par value; authorized 200.0 million shares; issued 2026 - 48.2 million shares and 2025 - 48.2 million shares Net income (loss), diluted Net Income (Loss) Available to Common Stockholders, Diluted Income Tax Contingency [Table] Current convertible notes, net Convertible Notes Payable, Current Preferred shares, authorized (in shares) Preferred Stock, Shares Authorized Summary of Current and Non-current Debt Schedule of Debt [Table Text Block] Shares surrendered for employee taxes on stock compensation Payment, Tax Withholding, Share-Based Payment Arrangement Repayments on convertible notes Repayments of Convertible Debt Cash paid to the noteholder Employee Stock [Member] Underwater Options Revenue Recognition Revenue from Contract with Customer [Text Block] Entity Registrant Name Entity Registrant Name Financing Arrangements Debt Disclosure [Text Block] Shares surrendered for taxes (in shares) Treasury Stock, Shares, Acquired Other Nonoperating Income (Expense), Total Total other (income) expense, net Other (income) expense, net Other Nonoperating Income (Expense) Accumulated Other Comprehensive Income Loss [Table] Accumulated Other Comprehensive Income (Loss) [Table] Subsequent Events [Abstract] Schedule of Other (Income) Expense, Net Schedule of Other Nonoperating Income (Expense) [Table Text Block] Income Tax Expense (Benefit), Total Provision (benefit) for income taxes Income Tax Expense (Benefit) Stock Repurchased During Period, Value Stock Repurchased, Amount Treasury Stock Reissued at Lower than Repurchase Price Average Repurchase price Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Schedule of Components of Convertible Notes Convertible Debt [Table Text Block] Payments for Restructuring Payments Shares granted Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Total Assets Assets Income Statement [Abstract] Retirement Plan Name [Domain] Earnings Per Share, Diluted, Total Diluted earnings (loss) per share Earnings Per Share, Diluted Diluted earnings (loss) per share TimkenSteel corporation bargaining unit pension plan. TimkenSteel Corporation Bargaining Unit Pension Plan [Member] Bargaining Plan City Area Code City Area Code Defined benefit plan annuitization settlement Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement Schedule of Defined Benefit Plans Disclosures Schedule of Defined Benefit Plans Disclosures [Table Text Block] Restricted Cash and Cash Equivalents, Current, Total Restricted Cash and Cash Equivalent, Current Restricted cash reported in other current assets Finance Lease, Liability, Noncurrent Non-current finance lease liabilities Debt Instrument, Face Amount Debt Instrument, Face Amount Stock-based compensation expense (in shares) Stock Issued During Period Shares Stock Based Compensation Stock issued during period, shares, stock-based compensation. Defined Benefit Plan [Table] Miscellaneous (income) expense Miscellaneous Nonoperating Income Expense Miscellaneous Nonoperating Income (Expense) Proceeds from Income Tax Refund, Federal Government Fund Received Government fund received, Retirement Plan Name [Axis] Property, Plant and Equipment, Net, Ending Balance Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net, Total Property, plant and equipment, net Property, Plant and Equipment, Net Incremental common shares attributable to share based payment arrangements shares assumed purchased. Incremental Common Shares Attributable To Share Based Payment Arrangements Shares Assumed Purchased Shares assumed purchased Retained Earnings [Member] Retained Earnings (Deficit) Aerospace and Defense [Member] Aerospace and Defense [Member] Aerospace and Defense Share-based Payment Arrangement, Noncash Expense, Total Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Non-current operating lease liabilities Operating Lease, Liability, Noncurrent Net Cash Provided (Used) by Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Change in Accounting Principle, Accounting Standards Update, Adopted [true false] Change In Accounting Principle Accounting Standards Update Adopted Deferred Income Tax Liabilities, Net, Total Deferred income taxes Deferred Income Tax Liabilities, Net Entity Interactive Data Current Entity Interactive Data Current Operating Activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Recent Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] Convertible Senior Notes due 2021 Convertible Senior Notes due 2021 Convertible Senior Notesdue Twenty Twenty One [Member] Convertible Senior Notes due Twenty Twenty One [Member] Entity Tax Identification Number Entity Tax Identification Number Long-Term Debt, Type [Axis] Manufacturing supplies Other Inventory, Supplies, Gross Income Tax Authority, Name [Domain] Local Phone Number Local Phone Number Accumulated Other Comprehensive Income Loss [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Net Periodic Benefit Cost (Income) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Denominator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Accounting Policies [Abstract] Capital expenditures Payments for Capital Improvements Debt instrument, threshold trading days Debt Instrument, Convertible, Threshold Trading Days Disaggregation of Revenue Line Items Disaggregation of Revenue [Line Items] Revenue from Contract with Customer, Excluding Assessed Tax, Total Net sales Revenue from Contract with Customer, Excluding Assessed Tax Credit Agreement Long-Term Line of Credit, Noncurrent Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company