Quarterly Financial Information Disclosure [Abstract] Summary of Quarterly Financial Data (unaudited) Quarterly Financial Information [Table Text Block] Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Derivative financial instruments: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract] Unrealized losses arising during the period, net of tax benefit of $0.3, $0.0, and $0.0 Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Currency translation adjustment: Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent [Abstract] Unrealized losses arising during the period, net of tax benefit of $0.3, $0.0, and $0.0 Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Reclassification adjustments for losses included in net income, net of tax benefit of $0.0, $0.0, and $0.0 Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Selected Quarterly Financial Data (Unaudited) Quarterly Financial Information [Text Block] Income Tax Disclosure [Abstract] Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Depreciation, depletion, and amortization Deferred Tax Liabilities, Property, Plant and Equipment Total deferred tax liabilities Deferred Tax Liabilities, Gross Deferred tax assets: Components of Deferred Tax Assets [Abstract] Workers compensation, pensions, and other benefits Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Warranties and reserves Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Warranty Reserves and Other Reserves Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Warranty Reserves and Other Reserves Tax loss carryforwards and credits Deferred Tax Assets, Tax Credit Carryforwards Inventory Deferred Tax Assets, Inventory Accrued liabilities and other Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities and Other Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities and Other Total deferred tax assets Deferred Tax Assets, Gross Net deferred tax assets (liabilities) before valuation allowances Deferred Tax Assets (Liabilities), Net, Before Valuation Allowance and Reserve for Uncertain Tax Provisions Deferred Tax Assets (Liabilities), Net, Before Valuation Allowance and Reserve for Uncertain Tax Provisions. Valuation allowances Deferred Tax Assets, Valuation Allowance Net deferred tax assets (liabilities) before reserve for uncertain tax positions Deferred Tax Assets (Liabilities), Net, Before Reserve for Uncertain Tax Provisions Deferred Tax Assets (Liabilities), Net, Before Reserve for Uncertain Tax Provisions. Deferred tax assets included in reserve for uncertain tax positions Deferred Tax Assets Included in Reserve for Uncertain Tax Positions Deferred tax assets included in reserve for uncertain tax positions. Adjusted net deferred tax assets (liabilities) Deferred Income Tax Liabilities, Net Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Capital lease obligations Capital Lease Obligations [Member] Line of credit Line of Credit [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving credit facility Revolving Credit Facility [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] 2019 Long-term Debt and Capital Lease Obligations, Repayments of Principal in Next Twelve Months 2020 Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four 2023 Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five Goodwill and Intangible Assets Disclosure [Abstract] Goodwill Goodwill Disclosure [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Construction Products Group Construction Products Group [Member] Construction products group. Energy Equipment Group Energy Equipment Group [Member] Energy Equipment Group. Transportation Products Group Transportation Products Group [Member] Transportation Products Group [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill Goodwill Goodwill, Impairment Loss Goodwill, Impairment Loss Equity [Abstract] Changes in accumulated other comprehensive loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Income Statement [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Other Income and Expenses [Abstract] Summary of other, net (income) expense Schedule of Other Nonoperating Income (Expense) [Table Text Block] Accounting Policies [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Arcosa Equity Awards Held by Arcosa Employees Common Stock [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Authorized amount from Board of Directors for share repurchase Stock Repurchase Program, Authorized Amount Number of shares repurchased (in shares) Treasury Stock, Shares, Acquired Cost of shares repurchased Treasury Stock, Value, Acquired, Cost Method Common stock, shares authorized Common Stock, Shares Authorized Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted share awards Restricted Share Awards [Member] Restricted Share Awards [Member] Restricted stock Restricted Stock [Member] Performance units Performance Shares [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Shares of common stock provided for awarding by the Plan (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Number of shares available for issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Stock-based compensation expense Allocated Share-based Compensation Expense Income tax benefit related to stock-based compensation expense Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Percentage of target grant potentially issuable depending on achievement of certain specified goals Share-based Compensation Arrangements by Share-based Payment Award, Allowance for Adjustment of Units Based on Target Level, Percent Share-based Compensation Arrangements by Share-based Payment Award, Allowance for Adjustment of Units Based on Target Level, Percent Unrecognized compensation expense related to restricted share awards Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Weighted average recognition period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Revenue from Contract with Customer [Abstract] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Wind towers and utility structures Wind towers and utility structures [Domain] Wind towers and utility structures Other Other [Member] Other [Member] Inland barge Inland barge [Domain] Inland barge [Domain] Transportation Products Group Transportation Products Group [Domain] Transportation Products Group [Domain] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Unsatisfied performance obligations, Amount Revenue, Remaining Performance Obligation, Amount Revenue, remaining performance obligation expected to be delivered in next year Revenue, remaining performance obligation expected to be delivered in next year Revenue, remaining performance obligation expected to be delivered in next year Revenues Revenues Operating costs: Costs and Expenses [Abstract] Cost of revenues Cost of Goods and Services Sold Selling, engineering, and administrative expenses Selling, General and Administrative Expense Impairment charge Asset Impairment Charges Operating profit Operating Income (Loss) Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision (benefit) for income taxes Income Tax Expense (Benefit) Net income per common share: Earnings Per Share [Abstract] Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] ASU 2016-02 contract assets as percentage of total assets ASU 2016-02 Contract Assets as Percentage of Total Assets ASU 2016-02 Contract Assets as Percentage of Total Assets Reduction in retained earnings due to adoption of ASU 2014-09 New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets Retirement Benefits [Abstract] Employee Retirement Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] ACG Materials ACG Materials [Member] ACG Materials [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Acquisition and divestiture activity Schedule Of Business Acquisitions And Dispositions [Table Text Block] Schedule Of Business Acquisitions And Dispositions [Table Text Block] Preliminary purchase price allocation Schedule of Business Acquisitions, by Acquisition [Table Text Block] Pro-forma consolidated and combined operating results Business Acquisition, Pro Forma Information [Table Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Buildings and improvements Building and Building Improvements [Member] Leasehold improvements Leasehold Improvements [Member] Machinery and other Machinery and Equipment [Member] Technology equipment Technology Equipment [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Estimated useful life Property, Plant and Equipment, Useful Life Balance without adjustment for ASU 2014-09 Balance without adjustment for ASU 2014-09 [Domain] Balance without adjustment for ASU 2014-09 [Domain] Cost of revenues Provision for income taxes Receivables, net of allowance Accounts Receivable, Net, Current Raw materials and supplies Inventory, Raw Materials and Supplies, Net of Reserves Work in process Inventory, Work in Process, Net of Reserves Finished goods Inventory, Finished Goods, Net of Reserves Accrued liabilities Accrued Liabilities, Current Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Capital in excess of par value Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Provision for deferred income taxes Deferred Income Tax Expense (Benefit) (Increase) decrease in receivables Increase (Decrease) in Accounts Receivable (Increase) decrease in inventories Increase (Decrease) in Inventories Increase (decrease) in accrued liabilities Increase (Decrease) in Accrued Liabilities Net cash provided (required) by operating activities Net Cash Provided by (Used in) Operating Activities Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract Derivative Contract [Domain] Interest rate hedges Interest Rate Swap [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as hedging instrument Designated as Hedging Instrument [Member] Letter of credit Letter of Credit [Member] Credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Credit facility, margin on LIBOR interest rate Debt Instrument, Basis Spread on Variable Rate Line of credit commitment fee percentage Line of Credit Facility, Commitment Fee Percentage Revolving credit facility Line of Credit Facility, Amount Outstanding Exclusive of Letters of Credit Line of Credit Facility, Amount Outstanding Exclusive of Letters of Credit Letters of credit outstanding Letters of Credit Outstanding, Amount Credit facility, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Unamortized debt issuance costs Unamortized Debt Issuance Expense Derivative, notional amount Derivative, Notional Amount Derivative fixed interest rate Derivative, Fixed Interest Rate Derivative liability Derivative Liability Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Total current Current Income Tax Expense (Benefit) Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Effect of tax cuts and jobs act - Deferred federal Effect of tax cuts and jobs act - Deferred Federal Income Tax Expense (Benefit) Effect of tax cuts and jobs act - Deferred Federal Income Tax Expense (Benefit) Other - Deferred federal Other - Deferred Federal Income Tax Expense (Benefit) Other - Deferred Federal Income Tax Expense (Benefit) Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Total deferred Property, Plant and Equipment [Abstract] Property, Plant, and Equipment Property, Plant and Equipment Disclosure [Text Block] Segment Reporting [Abstract] Financial information for segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenues, operating profit, total assets, and long-lived assets for Mexico operations Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Trinity Equity Awards Held by Arcosa Employees Trinity Common Stock [Member] Trinity Common Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Number of Equity Awards, Restricted share awards outstanding, Beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Number of Equity Awards, Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Number of Equity Awards, Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Number of Equity Awards, Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Number of Equity Share Awards, Restricted share awards outstanding, Ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Weighted Average Grant-Date Fair Value per Award, Equity awards outstanding, Beginning balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value per Award, Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value per Award, Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value per Award, Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value per Award, Equity awards outstanding, Ending balance (in dollars per share) Acquisitions and Divestitures Mergers, Acquisitions and Dispositions Disclosures [Text Block] Unrealized gains (losses) arising during the period, tax expense (benefit) Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Unrealized gains (losses) arising during the period, tax expense (benefit) Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Amortization of net actuarial losses, tax benefit Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax Schedule of Benefit Plans Disclosures [Table] Schedule of Benefit Plans Disclosures [Table] Schedule of Benefit Plans Disclosures [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other assets Other Assets [Member] Schedule of Benefit Plans Disclosures [Line Items] Schedule of Benefit Plans Disclosures [Line Items] [Line Items] for Schedule of Benefit Plans Disclosures [Table] Employee retirement plan expense Pension Cost (Reversal of Cost) Company's contributions to multiemployer plan as a percentage of total contributions (less than) Multiemployer Plan, Collective-Bargaining Arrangement, Percentage of Contributions Required for Multiple Collective-Bargaining Arrangements Plan assets Defined Benefit Plan, Plan Assets, Amount Projected benefit obligation Defined Benefit Plan, Benefit Obligation Funded status of plan Defined Benefit Plan, Funded (Unfunded) Status of Plan Expected employer contributions to 401(k) plans and Supplemental Profit Sharing Plan next year, including amount funded by Former Parent Defined Contribution Plans, Estimated Future Employer Contributions in Next Fiscal Year, Including Amounts Funded by Former Parent Defined Contribution Plans, Estimated Future Employer Contributions in Next Fiscal Year, Including Amounts Funded by Former Parent Expected employer contributions to 401(k) plans and Supplemental Profit Sharing Plan next year Defined Contribution Plans, Estimated Future Employer Contributions in Next Fiscal Year Defined Contribution Plans, Estimated Future Employer Contributions in Next Fiscal Year Multiemployer plan, expected contributions in following year Multiemployer Plan, Estimated Future Contributions in Next Fiscal Year Multiemployer Plan, Estimated Future Contributions in Next Fiscal Year Multiemployer plan contributions Multiemployer Plan, Contributions by Employer Company contributions to the Profit Sharing Plan as a percentage of eligible compensation based on service Defined Contribution Plan, Employer Contribution Based on Service, Percentage Defined Contribution Plan, Employer Contribution Based on Service, Percentage Statement [Table] Statement [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Corporate Corporate, Non-Segment [Member] Statement [Line Items] Statement [Line Items] Corporate overhead costs allocated from Former Parent Cost, Overhead Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Environmental matters Environmental and Workplace Matters [Member] Environmental and Workplace Matters Accrued liabilities Accrued Liabilities [Member] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Inventories Inventories [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Total accrual Loss Contingency Accrual Range of reasonably possible losses Loss Contingency, Estimate of Possible Loss Non-cancelable purchase obligations Unrecorded Unconditional Purchase Obligation Document and Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Shell Company Entity Shell Company Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Public Float Entity Public Float Other Transactions with Trinity Businesses Schedule of Related Party Transactions [Table Text Block] Unsatisfied Performance Obligations Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] ASU 2014-09 Impact Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Schedule of restricted stock activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Goodwill impairment charges Net book value of intangible assets Intangible Assets, Net (Excluding Goodwill) Indefinite-lived intangible assets (excluding goodwill) Indefinite-lived Intangible Assets (Excluding Goodwill) Intangible assets, gross Intangible Assets, Gross (Excluding Goodwill) Intangible assets with defined useful lives, amortization period Finite-Lived Intangible Asset, Useful Life Amortization expense from intangible assets Amortization of Intangible Assets Statement of Stockholders' Equity [Abstract] Former Parent's Net Investment Former Parent's Net Investment [Member] Former Parent's Net Investment [Member] Common Stock Capital in Excess of Par Value Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Treasury Stock Treasury Stock [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance Stockholders' Equity Attributable to Parent Beginning balance, shares Shares, Issued Cumulative effect of adopting new accounting standards (see Note 1) CumulativeEffectofNewAccountingPrincipleinPeriodofAdoption(Duration) CumulativeEffectofNewAccountingPrincipleinPeriodofAdoption(Duration) Net income Other comprehensive income Capital contribution from Former Parent Capital Contribution From Former Parent, Equity Capital Contribution From Former Parent, Equity Net transfers from Former Parent and affiliates Net Transfers From To Former Parent and Affiliates Net Transfers From To Former Parent and Affiliates Distribution by Former Parent Distribution by Former Parent Distribution by Former Parent Distribution by Former Parent, shares Distribution by Former Parent, Shares Distribution by Former Parent, Shares Cash dividends on common stock Dividends, Common Stock, Cash Restricted shares, net Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Restricted shares, net, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Shares repurchased Shares repurchased, shares Ending balance Ending balance, shares Capital lease obligations Capital Lease Obligations Total debt Debt and Capital Lease Obligations Inventory write down Inventory Write-down Computation of basic and diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Goodwill by segment Schedule of Goodwill [Table Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Relationship with Former Parent and Related Entities Related Party Transactions Disclosure [Text Block] Stockholders' Equity Stockholders' Equity, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Financial Instruments, Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Financial Instruments, Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Inventories Inventory, Policy [Policy Text Block] Property, Plant, and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Long-lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Insurance Self Insurance Reserve [Policy Text Block] Warranties Standard Product Warranty, Policy [Policy Text Block] Derivatives Instruments Derivatives, Policy [Policy Text Block] Foreign Currency Translation Foreign Currency Transactions and Translations Policy [Policy Text Block] Other Comprehensive Income (Loss) Comprehensive Income, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Management's Estimates Use of Estimates, Policy [Policy Text Block] Earnings Per Common Share Earnings Per Share [Text Block] Income Taxes Income Tax Disclosure [Text Block] Income Tax Contingency [Table] Income Tax Contingency [Table] Nature of Uncertainty [Axis] Nature of Uncertainty [Axis] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Nature of Uncertainty [Domain] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Nature of Uncertainty [Domain] Settlement with taxing authority and lapse in statute of limitations Settlement with Taxing Authority and Lapse in Statute of Limitations [Member] Settlement with Taxing Authority and Lapse in Statute of Limitations [Member] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effect of tax cuts and jobs act - Deferred federal Income before income taxes for U.S. operations Income (Loss) from Continuing Operations before Income Taxes, Domestic Income before income taxes for foreign operations Income (Loss) from Continuing Operations before Income Taxes, Foreign Net operating loss carryforwards - domestic Deferred Tax Assets, Operating Loss Carryforwards, Domestic Net operating loss carryforwards - foreign Deferred Tax Assets, Operating Loss Carryforwards, Foreign Remaining state loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, State and Local Additions for tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Additions for tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Reduction in tax positions of prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Unrecognized tax benefits including interest and penalties that would affect the Company's effective tax rate if recognized Unrecognized Tax Benefits that Would Impact Effective Tax Rate Reasonably possible decrease in unrecognized federal and state tax benefits within twelve months Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Total accrued interest and penalties related to uncertain tax positions Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Increase (decrease) in income tax expense related to interest and penalties on unrecognized tax benefits Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Fair Value Disclosures [Abstract] Assets and liabilities measured at fair value on recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] AOCI Attributable to Parent Currency translation adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Unrealized loss on derivative financial instruments Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Beginning balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Other comprehensive income (loss), net of tax, before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive loss, net of tax Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Amounts reclassified from accumulated other comprehensive loss, tax benefit Reclassification from AOCI, Current Period, Tax Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Ending balance Total weighted average restricted shares and antidilutive stock options Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Earnings Per Share Reconciliation [Abstract] Earnings Per Share Reconciliation [Abstract] Unvested restricted share participation Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Net income – basic Net Income (Loss) Available to Common Stockholders, Basic Net income - basic (shares) Weighted Average Number of Shares Outstanding, Basic Net income - basic (EPS) Effect of dilutive securities: Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Nonparticipating unvested restricted shares Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units Nonparticipating unvested restricted shares (shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Net income – diluted Net Income (Loss) Available to Common Stockholders, Diluted Net income - diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Net income - diluted (EPS) Acquisitions and Divestitures [Abstract] Acquisitions and Divestitures [Abstract] Revenues Business Acquisition, Pro Forma Revenue Income before income taxes Business Acquisition, Pro Forma Income Before Income Taxes Business Acquisition, Pro Forma Income Before Income Taxes Components of debt Schedule of Debt [Table Text Block] Remaining principal payments under existing debt agreements Schedule of Maturities of Long-term Debt [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Eliminations Consolidation, Eliminations [Member] Construction aggregates Construction aggregates [Domain] Construction aggregates [Domain] Steel components Steel components [Domain] Steel components [Domain] All Other Other Segments [Member] Intersegment Intersegment Eliminations [Member] Total Operating Segments [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Operating Profit (Loss) Assets Assets Depreciation, Depletion, & Amortization Depreciation, Depletion and Amortization Capital Expenditures Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Stock issued for acquisition (value) Stock Issued During Period, Value, Acquisitions Income tax payments made, net Income Taxes Paid, Net Interest income Interest Income, Other Foreign currency exchange transactions Foreign Currency Transaction Gain (Loss), before Tax Other Other Income (Expense), Nonoperating Other Income (Expense), Nonoperating Other, net (income) expense Other Nonoperating Income (Expense) Statement of Financial Position [Abstract] Receivables, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Treasury stock, shares Treasury Stock, Shares Debt Debt Disclosure [Text Block] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair value measurements, recurring Fair Value, Measurements, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Interest rate hedges 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] Assets: Assets, Fair Value Disclosure [Abstract] Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Total assets Assets, Fair Value Disclosure Liabilities: Liabilities, Fair Value Disclosure [Abstract] Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Trinity Industries, Inc. Trinity Industries, Inc. [Member] Trinity Industries, Inc. [Member] Sales by Arcosa to Trinity businesses Purchases by Arcosa from Trinity businesses Cost of Revenue Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Product Information [Table] Schedule of Product Information [Table] Accounts Receivable Accounts Receivable [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Revenue Sales [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer Concentration Risk Customer Concentration Risk [Member] Product Information [Line Items] Product Information [Line Items] Concentration Risk, Percentage Concentration Risk, Percentage Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Beginning balance Unrecognized Tax Benefits Reductions for tax positions of prior years Settlements Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Expiration of statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Ending balance ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Receivables, net of allowance for doubtful accounts of $8.7 and $8.6 Inventories: Inventory, Net [Abstract] Total inventory Inventory, Net Other Other Assets, Current Total current assets Assets, Current Property, plant, and equipment, net Property, Plant and Equipment, Net Deferred income taxes Deferred Tax Assets, Net, Noncurrent Other assets Other Assets, Noncurrent Assets LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Liabilities, Current [Abstract] Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Current portion of long-term debt Long-term Debt and Capital Lease Obligations, Current Total current liabilities Liabilities, Current Debt Long-term Debt and Capital Lease Obligations Other liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Stockholders’ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Former Parent's net investment Stockholders' Equity, Parent Company Investment, Net Stockholders' Equity, Parent Company Investment, Net Common stock, $0.01 par value – 200.0 shares authorized at December 31, 2018; 0.0 at December 31, 2017; 48.8 shares issued and outstanding at December 31, 2018; 0.0 at December 31, 2017 Common Stock, Value, Issued Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock – 0.1 shares at December 31, 2018; 0.0 at December 31, 2017 Treasury Stock, Value Total stockholders' equity Total liabilities and stockholders' equity Liabilities and Equity Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Mexico: MEXICO External External Customers [Member] External Customers [Member] Intercompany Intercompany [Member] Intercompany [Member] Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Total Assets Long-Lived Assets Long-Lived Assets Components of property, plant, and equipment Property, Plant and Equipment [Table Text Block] Impairment of long-lived assets held-for-use Impairment of Long-Lived Assets Held-for-use Components of the provision for income taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Reconciliation between the statutory U.S. Federal income tax rate and the Company's effective income tax rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Components of deferred tax liabilities and assets Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Change in unrecognized tax benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Operating costs: Operating Expenses [Abstract] Selling, engineering, and administrative expenses Total operating costs Operating Expenses Total operating profit Interest expense Interest Expense Other, net (income) expense Total other (income) expense Nonoperating Income (Expense) Income before income taxes Provision (benefit) for income taxes: Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Deferred Total provision for income taxes Net income Weighted average number of shares outstanding(1): Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Diluted (in shares) Dividends declared per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared Other, Net Other Income and Other Expense Disclosure [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Inventories Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Property, plant, and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Mineral reserves Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Mineral Reserves Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Mineral Reserves Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued and other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Capital lease obligations Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Capital Lease Obligation Deferred income taxes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent Total net assets acquired Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Details of multiemployer plan Schedule of Multiemployer Plans [Table Text Block] Fair Value Accounting Fair Value Disclosures [Text Block] Land Land [Member] Buildings and improvements Machinery and other Construction in progress Construction in Progress [Member] Property, plant and equipment, at cost Property, Plant and Equipment, Gross Less: accumulated depreciation and depletion Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Depletable land Depletable land Depletable land Nonoperating plants Manufacturing Facility, Nonoperating [Member] Manufacturing Facility, Nonoperating [Member] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Inland barge business Inland barge business [Member] Inland barge business [Member] Lightweight aggregates business, May 2017 Lightweight aggregates business, May 2017 [Member] Lightweight aggregates business, May 2017 [Member] Trench shoring products business Trench Shoring Products [Member] Trench Shoring Products [Member] Purchase price Business Combination, Consideration Transferred Borrowing to fund acquisition purchase price Business Combination, Consideration Transferred, Amount Funded with New Borrowings Business Combination, Consideration Transferred, Amount Funded with New Borrowings Revenues from acquiree included in Statement of Operations Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Net cash paid Payments to Acquire Businesses, Net of Cash Acquired Goodwill recorded Goodwill, Acquired During Period Revenues from divested businesses Disposal Group, Including Discontinued Operation, Revenue Number of divestitures Number of Divestitures Number of Divestitures Schedule of Multiemployer Plans [Table] Schedule of Multiemployer Plans [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Boilermaker-Blacksmith National Pension Trust Boilermaker-Blacksmith National Pension Trust [Member] Boilermaker-Blacksmith National Pension Trust [Member] Multiemployer Plans [Line Items] Multiemployer Plans [Line Items] Employer Identification Number Entity Tax Identification Number PPA Zone Status Multiemployer Plans, Certified Zone Status [Fixed List] Financial improvement plan status Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List] Surcharge imposed Multiemployer Plans, Surcharge [Fixed List] Expiration date of collective bargaining agreement Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date State taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Domestic production activities deduction Effective Income Tax Rate Rec, Qualified Prod Activity Effective Income Tax Rate Rec, Qualified Prod Activity Changes in valuation allowances and reserves Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Changes in tax reserves EffectiveIncomeTaxRateReconciliationChangesInTaxReserves EffectiveIncomeTaxRateReconciliationChangesInTaxReserves Effect of Tax Cuts and Jobs Act Effective Income Tax Rate Reconciliation, Effect of Tax Cuts and Jobs Act, Percent Effective Income Tax Rate Reconciliation, Effect of Tax Cuts and Jobs Act, Percent Prior year true ups Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Percent Foreign adjustments Effective Income Tax Rate Reconciliation, Tax Settlement, Foreign, Percent Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective rate Effective Income Tax Rate Reconciliation, Percent Product Warranty Liability [Table] Product Warranty Liability [Table] Product Warranty Liability [Line Items] Product Warranty Liability [Line Items] Product warranty period against materials and manufacturing defects Product Warranty Period Product warranty period. Warranty accrual Standard Product Warranty Accrual, Current Operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation, depletion, and amortization Stock-based compensation expense Share-based Compensation Gain on disposition of property and other assets Gain (Loss) on Disposition of Property Plant Equipment (Increase) decrease in other assets Increase (Decrease) in Other Noncurrent Assets Increase (decrease) in other liabilities Increase (Decrease) in Other Noncurrent Liabilities Other Other Noncash Income (Expense) Changes in current assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] (Increase) decrease in other current assets Increase (Decrease) in Other Current Assets Increase (decrease) in accounts payable Increase (Decrease) in Accounts Payable Net cash provided by operating activities Investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Proceeds from disposition of property and other assets Proceeds from Sale of Property, Plant, and Equipment Capital expenditures Payments to Acquire Property, Plant, and Equipment Acquisitions, net of cash acquired Proceeds from divestitures Proceeds from Divestiture of Businesses, Net of Cash Divested Net cash required by investing activities Net Cash Provided by (Used in) Investing Activities Financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Payments to retire debt Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities Proceeds from issuance of debt Proceeds from Issuance of Long-term Debt and Capital Securities, Net Shares repurchased Payments for Repurchase of Common Stock Capital contribution from Former Parent Capital Contribution From Former Parent Capital Contribution From Former Parent Net transfers from/(to) Former Parent and affiliates Net Transfers From To Parent and Affiliates Net Transfers From To Parent and Affiliates Other Proceeds from (Payments for) Other Financing Activities Net cash provided by (required by) financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Acquisitions: Business Combination, Consideration Transferred [Abstract] Segment Information Segment Reporting Disclosure [Text Block]