Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Portion at fair value measurement Portion at Fair Value Measurement [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Title of 12(b) Security Title of 12(b) Security Carrying amount Reported Value Measurement [Member] Document Fiscal Year Focus Document Fiscal Year Focus Acquisition related costs Business Combination, Acquisition-Related Cost, Expense Remaining performance obligations, expected timing Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Adjustment to Compensation, Amount Adjustment to Compensation Amount Letters of credit set to expire, year two Letters of Credit Set to Expire, Year Two Letters of Credit Set to Expire, Year Two Segment Reporting [Abstract] Segment Reporting [Abstract] Montana Ready-Mix Concrete Business Montana Ready-Mix Concrete Business [Member] Montana Ready-Mix Concrete Business Schedule of Estimated Amortization Expense Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block] Common stock, 300,000,000 shares authorized, $0.01 par value, 57,194,556 shares issued and 56,763,420 shares outstanding at September 30, 2026; 57,095,301 shares issued and 56,664,165 shares outstanding at September 30, 2025; 57,095,301 shares issued and 56,664,165 shares outstanding at December 31, 2025 Common Stock, Value, Issued Tax withholding on stock-based compensation Payment, Tax Withholding, Share-Based Payment Arrangement Accrued compensation Employee-related Liabilities, Current Schedule of Long-Term Debt Outstanding Schedule of Long-Term Debt Instruments [Table Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Aggregates Aggregates [Member] Aggregates Potential liabilities related to litigation and environmental matters Loss Contingency Accrual Guarantor obligations, maximum exposure, undiscounted Guarantor Obligations, Maximum Exposure, Undiscounted Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Contract asset Contract with Customer, Asset, after Allowance for Credit Loss Number of reportable segments aligned with product line Number Of Reportable Segments Aligned With Product Line Number Of Reportable Segments Aligned With Product Line Fair value by measurement frequency [Axis] Measurement Frequency [Axis] Proceeds from disposition of business Proceeds from Divestiture of Businesses Less expected credit loss Beginning balance Ending balance Accounts Receivable, Allowance for Credit Loss Net proceeds from sale or disposition of property and other Proceeds from Sale of Productive Assets Amendment Flag Amendment Flag Consolidated Entities [Axis] Consolidated Entities [Axis] Goodwill [Line Items] Goodwill [Line Items] Current liabilities: Liabilities, Current [Abstract] Provision for credit losses Current expected credit loss provision Accounts Receivable, Credit Loss Expense (Reversal) Entity common stock, shares outstanding Entity Common Stock, Shares Outstanding Disposal Group Classification [Axis] Disposal Group Classification [Axis] Property, plant, and equipment acquired Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Loss Contingencies [Table] Loss Contingencies [Table] Consolidated Entities [Domain] Consolidated Entities [Domain] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Schedule of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Loss contingency receivable Loss Contingency, Receivable Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Capital expenditures Segment Reporting, Long-Lived Asset, Expenditure for Addition Retention receivables Construction Contractor, Receivable, Retainage Noncurrent liabilities: Liabilities, Noncurrent [Abstract] Other intangible assets, net Total Intangible Asset, Excluding Goodwill, after Accumulated Amortization Increase in line of credit facility Line of Credit Facility, Maximum Borrowing Capacity, Increase Line of Credit Facility, Maximum Borrowing Capacity, Increase Basic (in shares) Weighted average common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Contract assets Contract assets Contract with Customer, Asset, after Allowance for Credit Loss, Current Liquid asphalt Liquid Asphalt [Member] Liquid Asphalt Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair value, by balance sheet grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Number of reportable segments Number of Reportable Segments Total current liabilities  Liabilities, Current Contract with customer, performance obligation satisfied in previous period Contract with Customer, Performance Obligation Satisfied in Previous Period Customer relationships Customer Relationships [Member] Other noncurrent changes Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net Entity Address, City or Town Entity Address, City or Town Schedule of Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Mountain Mountain Segment [Member] This segment mines, processes and sells construction aggregates. It also produces and sells asphalt and ready-mix concrete. In addition this segment preforms integrated contracting services. This segment operates in Idaho, Montana and Wyoming. Receivables [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Basis of presentation Basis of Accounting, Policy [Policy Text Block] Construction materials Product [Member] Receivables past due 90 days Accounts Receivable, Noncurrent, 90 Days or More Past Due, Still Accruing Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Trade receivables Accounts and Other Receivables, Net, Current Receivables, gross Accounts Receivable, before Allowance for Credit Loss Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Less accumulated amortization Intangible Asset, Finite-Lived, Accumulated Amortization Receivable [Domain] Receivable [Domain] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Long-term debt - current portion Less current maturities Long-Term Debt, Current Maturities Other corporate expenses Other Expenses Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Revenue, Description Of Timing [Axis] Revenue, Description Of Timing [Axis] Revenue, Description Of Timing Central Central Central Segment [Member] This segment mines, processes and sells construction aggregates. It also produces and sells asphalt and ready-mix concrete. This segment also manufactures prestressed concrete products. In addition this segment preforms integrated contracting services. This segment operates in Iowa, Minnesota, North Dakota and South Dakota. Net Income (Loss) Per Share Earnings Per Share, Policy [Policy Text Block] New accounting standards New Accounting Pronouncements, Policy [Policy Text Block] Lawsuits filed Loss Contingency, New Lawsuits Filed, Number Loss Contingency, New Lawsuits Filed, Number Property, plant and equipment additions in accounts payable Capital Expenditures Incurred but Not yet Paid Segment Reporting Segment Reporting [Table Text Block] Use of estimates Use of Estimates, Policy [Policy Text Block] Amortization of debt issuance costs Amortization of Debt Issuance Costs Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total long-term debt Long-Term Debt Current liabilities acquired Business Combination, Recognized Liability Assumed, Liability, Current Document Period End Date Document Period End Date Changes in current assets and liabilities, net of acquisitions: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Change in contract liabilities Contract with Customer, Liability, Current Change Amount of increase (decrease) in current contract liabilities Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Security Exchange Name Security Exchange Name Treasury stock held at cost - 431,136 shares Treasury Stock, Common, Value Consolidation, Eliminations Consolidation, Eliminations [Member] Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Corporate, Non-Segment & Intersegment Eliminations Corporate, Non-Segment & Intersegment Eliminations [Member] Corporate, Non-Segment & Intersegment Eliminations Accumulated other comprehensive loss Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Uncompleted Contracts Uncompleted Contracts [Text Block] Uncompleted contracts Current operating lease liabilities Operating Lease, Liability, Current Common stock issued for board of director fees (in shares) Stock Issued During Period, Shares, Issued for Services Schedule of Details of Expected Credit Losses Accounts Receivable, Allowance for Credit Loss [Table Text Block] Accrued interest Interest Payable, Current Contract receivables Billed Contracts Receivable Business segment data Segment Reporting, Policy [Policy Text Block] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Net Income Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Net income per share Earnings Per Share [Abstract] Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Schedule of Reconciliation of the Weighted-Average Common Shares Outstanding on a Basic and Diluted Basis Schedule of Weighted Average Number of Shares [Table Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Receivables Increase (Decrease) in Accounts and Notes Receivable Total liabilities  Liabilities Trading Symbol Trading Symbol Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Company Selected Measure Name Company Selected Measure Name Schedule of Restrictions on Cash and Cash Equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] Letters of credit set to expire in next fiscal year Letters of Credit Set to Expire in Next Fiscal Year Letters of credit set to expire in next fiscal year. Reclassification, Type [Axis] Reclassification, Type [Axis] Revenue, Description Of Timing, 25 Months Or More Revenue, Description Of Timing, 25 Months Or More [Member] Revenue, Description Of Timing, 25 Months Or More Long-term debt, gross Long-Term Debt, Gross Credit Facility [Domain] Credit Facility [Domain] Noncompete agreements Noncompete Agreements [Member] Operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Diluted (in shares) Weighted average common shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Backlog Order or Production Backlog [Member] Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Disposal Group Name [Domain] Disposal Group Name [Domain] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Money market funds Cash Equivalent, Money Market Fund, Carrying Value Amount outstanding under guarantees that is reflected on balance sheet Guarantor Obligations, Current Carrying Value Gross profit Gross Profit Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Effect of dilutive performance shares and restricted stock units (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Other Other Intangible Assets [Member] Cash, cash equivalents and restricted cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Award Timing Predetermined Award Timing Predetermined [Flag] Treasury Stock Treasury Stock, Common [Member] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Outstanding letters of credit Letters of Credit Outstanding, Amount Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Fair value measurements Fair Value of Financial Instruments, Policy [Policy Text Block] All Executive Categories All Executive Categories [Member] Number of states in which entity operates Number of States in which Entity Operates Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Long-term debt, fair value Long-Term Debt, Fair Value Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Business Segment Data Segment Reporting [Text Block] Minimum Minimum [Member] Reclassification, Type [Domain] Reclassification, Type [Domain] Ready-mix concrete Ready-mix concrete [Member] Ready-mix concrete Expiration Date Trading Arrangement Expiration Date Increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation 2030 Long-Term Debt, Maturity, Year Four Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Investments Payments for (Proceeds from) Investments Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] 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] Business Combination [Line Items] Business Combination [Line Items] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Common stock, authorized (in shares) Common Stock, Shares Authorized Consolidation and Elimination [Axis] Consolidation and Elimination [Axis] Consolidation and Elimination Exercise Price Award Exercise Price Investing activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Fair value, measurements, recurring Fair Value, Recurring [Member] Segment Reporting [Line Items] Segment Reporting [Line Items] Document Quarterly Report Document Quarterly Report Insurance contracts Cash Surrender Value, Fair Value Disclosure Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Receivables, net Accounts Receivable, after Allowance for Credit Loss Debt Debt Disclosure [Text Block] Repayment of long-term debt Repayments of Long-Term Debt Disposal Group Classification [Domain] Disposal Group Classification [Domain] Less unamortized debt issuance costs Debt Issuance Costs, Net Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Business Combination [Table] Business Combination [Table] Acquisitions and Dispositions Mergers, Acquisitions and Dispositions Disclosures [Text Block] Equity component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Operating Segments Excluding Intersegment Elimination Operating Segments Excluding Intersegment Elimination [Member] Operating Segments Excluding Intersegment Elimination Adoption Date Trading Arrangement Adoption Date Thereafter Long-Term Debt, Maturity, after Year Five Inventories Inventory, Policy [Policy Text Block] Total stockholders' equity Beginning balance Ending balance Equity, Attributable to Parent Assets Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Insider Trading Policies and Procedures [Line Items] Goodwill, measurement period adjustment Measurement Period Adjustments Goodwill, Measurement Period Adjustment Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Letters of credit set to expire current year Letters of Credit Set to Expire Current Year Letters of credit set to expire current year. Deferred income taxes Deferred Income Tax Expense (Benefit) Selling, general and administrative expenses Selling, general and administrative expenses excluding depreciation, depletion and amortization Selling, General and Administrative Expense Corporate Services and Eliminations Corporate Services, Segment [Member] Corporate Services, Segment Interest expense, net Interest Income (Expense), Nonoperating Business Combination [Domain] Business Combination [Domain] Letter of Credit Letter of Credit [Member] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Number of operating segments Number of Operating Segments Shares excluded from the calculation of diluted income per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Changes in the Carrying Amount of Goodwill Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key 2025 Aggregate Acquisitions 2025 Aggregate Acquisitions [Member] 2025 Aggregate Acquisitions Other paid-in capital Additional Paid in Capital, Common Stock All Adjustments to Compensation All Adjustments to Compensation [Member] Corporate, Non-Segment Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Business Combination [Axis] Business Combination [Axis] Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Remainder of 2026 Long-Term Debt, Maturity, Remainder of Fiscal Year Stockholders' equity: Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Strata Corporation Strata Corporation [Member] Strata Corporation Fair value, hierarchy [Axis] Fair Value Hierarchy and NAV [Axis] 2026 Aggregate Acquisitions 2026 Aggregate Acquisitions [Member] 2026 Aggregate Acquisitions Cost of revenue: Operating Expenses [Abstract] Intersegment Eliminations Intersegment Eliminations [Member] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Reduction in interest rate Debt Instrument, Interest Rate, Increase (Decrease) Schedule of Other Amortizable Intangible Assets Intangible Asset, Finite-Lived [Table Text Block] City Area Code City Area Code Change in contract assets Contract with Customer, Asset, Net Current Change Amount of increase (decrease) in current contract assets, net Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Name Forgone Recovery, Individual Name Commitments and contingencies Commitments and Contingencies, Policy [Policy Text Block] Reclassification, Other Reclassification, Other [Member] Contracting services public-sector Contracting services public-sector [Member] Contracting services public-sector Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Montana Aggregate-Based Operations Montana Aggregate-Based Operations [Member] Montana Aggregate-Based Operations Total noncurrent assets  Assets, Noncurrent Statement [Line Items] Statement [Line Items] Total assets Assets Assets Operating Segments Operating Segments [Member] Interest expense Interest Expense, Nonoperating PEO PEO [Member] Equity in earnings of unconsolidated affiliates Equity In Results Of Operations From Unconsolidated Affiliates Equity In Results Of Operations From Unconsolidated Affiliates 2028 Long-Term Debt, Maturity, Year Two Receivables and Allowance for Expected Credit Losses Credit Loss, Financial Instrument [Text Block] Measurement Basis [Axis] Measurement Basis [Axis] Other Other Liabilities, Noncurrent Goodwill Goodwill Goodwill, beginning balance Goodwill, ending balance Goodwill Net contract assets (liabilities) Contract with Customer, Assets and Liabilities, Current, Net Total of net contract assets and liabilities Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Goodwill Acquired During the Year Goodwill, Acquired During Period Amounts included in contract liability at the beginning of the period Contract with Customer, Liability, Revenue Recognized Discontinued Operations, Disposed of by Sale Discontinued Operations, Disposed of by Sale [Member] Retained Earnings Retained Earnings [Member] Noncurrent operating lease liabilities Operating Lease, Liability, Noncurrent Other taxes payable Taxes Payable, Current Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Schedule of Fair Value of Long-Term Debt Fair Value, by Balance Sheet Grouping [Table Text Block] Debt issuance costs Payments of Debt Issuance Costs Diluted (in dollars per share) Net income per share - diluted (in dollars per share) Earnings Per Share, Diluted Entity Current Reporting Status Entity Current Reporting Status Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Unrealized gains on investments Unrealized Gain (Loss) on Investments Amortization of intangible assets Intangible Asset, Finite-Lived, Amortization Expense Intangible Asset, Finite-Lived [Line Items] Intangible Asset, Finite-Lived [Line Items] Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] 2029 Long-Term Debt, Maturity, Year Three Less write-offs charged against the allowance Accounts Receivable, Allowance for Credit Loss, Writeoff Financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Net property, plant and equipment Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Amortization of postretirement liability losses included in net periodic benefit cost, net of tax of $41 and $21 for the three months ended and $123 and $61 for the nine months ended September 30, 2026 and 2025, respectively. Expenses amortized to other income Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax Other corporate revenue Other Income Inventories Inventory Disclosure [Text Block] Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Goodwill and Other Intangible Assets Intangible Asset and Goodwill [Text Block] Underlying Securities Award Underlying Securities Amount Schedule of Accounting Standards Update and Change in Accounting Principle Accounting Standards Update and Change in Accounting Principle [Table Text Block] Fair value Estimate of Fair Value Measurement [Member] Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] Revenue, Description Of Timing [Domain] Revenue, Description Of Timing [Domain] Revenue, Description Of Timing [Domain] Other current liabilities Increase (Decrease) in Other Current Liabilities Asphalt Asphalt [Member] Asphalt Inventories Increase (Decrease) in Inventories Gains on bargain purchases Gains on bargain purchases Business Combination, Bargain Purchase, Gain Recognized, Amount Segment Reporting [Table] Segment Reporting [Table] Schedule of Debt Maturities Schedule of Maturities of Long-Term Debt [Table Text Block] Revenue Business Combination, Acquiree's Revenue since Acquisition Date, Actual Prepayments and other current assets Other Assets, Current Weighted Average Interest Rate at September 30, 2026 Long-Term Debt, Weighted Average Interest Rate, at Point in Time Number of plant operations sold Disposal Group, Including Discontinued Operation, Number Of Plant Operations Sold Disposal Group, Including Discontinued Operation, Number Of Plant Operations Sold Commitments and contingencies Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating income Operating Income (Loss) Contracting services Service [Member] Remaining performance obligations Revenue, Remaining Performance Obligation, Amount Current Fiscal Year End Date Current Fiscal Year End Date Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Less write-offs charged against the allowance Accounts Receivable, Allowance for Credit Loss, Writeoff, Net Accounts Receivable, Allowance for Credit Loss, Writeoff, Net Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Common stock, issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Finished products Inventory, Finished Goods, Gross Treasury stock held at cost (in shares) Treasury stock, beginning balance (in shares) Treasury stock, ending balance (in shares) Treasury Stock, Common, Shares Current assets acquired Business Combination, Recognized Asset Acquired, Asset, Current Cost of revenue excluding depreciation, depletion and amortization Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Revenue, Description Of Timing, 12 Months Revenue, Description Of Timing, 12 Months [Member] Revenue, Description Of Timing, 12 Months Equity Components [Axis] Equity Components [Axis] Product and Service [Domain] Product and Service [Domain] Income taxes paid, net Income Tax Paid, after Refund Received Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Entity Interactive Data Current Entity Interactive Data Current Net income (loss) Business Combination, Acquiree's Earnings (Loss) since Acquisition Date, Actual Supplies and parts Other Inventory, Supplies, Gross Deferred income taxes Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Comprehensive income attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Amortization of postretirement liability losses included in net periodic benefit cost, tax Expenses reclassified from AOCI to income taxes Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Termination Date Trading Arrangement Termination Date Accounts payable Increase (Decrease) in Accounts Payable, Trade Total segment EBITDA Earnings Before Interest Tax Depreciation And Amortization Earnings Before Interest Tax Depreciation And Amortization Fair value, assets and liabilities measured on recurring and nonrecurring basis [Table] Fair Value, Recurring and Nonrecurring [Table] Finite-lived intangibles acquired Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Common stock issued for employee compensation, net of tax withholding Restricted Stock, Value, Shares Issued Net of Tax Withholdings Postretirement liability adjustment Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other accrued liabilities Other Liabilities, Current Investments and other Other Assets, Noncurrent Document Type Document Type Acquisitions, net of cash acquired Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Fair value measurements [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Gains on sales of assets Gain (Loss) on Disposition of Assets Schedule of Goodwill [Table] Goodwill [Table] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Issuance of long-term debt Proceeds from Issuance of Long-Term Debt Local Phone Number Local Phone Number Mandatory annual amortization Debt Instrument, Covenant, Mandatory Annual Amortization Debt Instrument, Covenant, Mandatory Annual Amortization Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Income before income taxes Consolidated income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Commitments and contingencies Commitments and Contingencies Intangible assets, gross Intangible Asset, Finite-Lived, before Accumulated Amortization Holdback payment Business Combination, Consideration Transferred, Holdback Payment Business Combination, Consideration Transferred, Holdback Payment Revenue Revenues Revenues Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Receivable Type [Axis] Receivable Type [Axis] Goodwill [Roll Forward] Goodwill [Roll Forward] Liabilities and Stockholders' Equity Liabilities and Equity [Abstract] Term loan A agreement due on March 7, 2030 5.42% Term Loan Agreement Due 2030 [Member] 5.42% Term Loan Agreement Due 2030 Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Tradename Trade Names [Member] Schedule of Assets Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Postretirement liability adjustment: Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax [Abstract] Inventories Total Inventory, Net All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Fair Value Measurements Fair Value Disclosures [Text Block] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Supplemental Cash Flow Information [Abstract] Supplemental Cash Flow Information [Abstract] West West Segment [Member] This segment mines, processes and sells construction aggregates. It also produces and sells asphalt and ready-mix concrete. This segment also manufactures prestressed concrete products. In addition this segment preforms integrated contracting services. This segment operates in Oregon and Washington. 2027 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] PEO Name PEO Name Restricted cash Restricted Cash Contract liability Contract with Customer, Liability Other segment items Segment Reporting, Other Segment Item, Amount Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Accounts Receivable, Allowance for Credit Loss [Roll Forward] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Common stock issued for employee compensation, net of tax withholding (in shares) Restricted Stock, Shares Issued Net of Shares for Tax Withholdings Change in net contract assets (liabilities) Contract with Customer, Assets and Liabilities, Net Current Change Amount of increase (decrease) in net contract assets and liabilities Disaggregation of revenue Revenue [Policy Text Block] Cash, cash equivalents and restricted cash Cash, cash equivalents and restricted cash -- beginning of year Cash, cash equivalents and restricted cash -- end of period Cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Schedule of Finite-Lived Intangible Assets by Major Class [Table] Intangible Asset, Finite-Lived [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Debt Instrument [Axis] Debt Instrument [Axis] Fair value by measurement frequency [Domain] Measurement Frequency [Domain] Other noncurrent liabilities acquired Business Combination, Recognized Liability Assumed, Other Liability, Noncurrent Employee stock-based compensation costs Share-Based Payment Arrangement, Noncash Expense 2028 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two Expected credit loss Credit Loss, Financial Instrument [Policy Text Block] Disposal Group Name [Axis] Disposal Group Name [Axis] Schedule of Inventory Schedule of Inventory, Current [Table Text Block] 2027 Long-Term Debt, Maturity, Year One Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Basic (in dollars per share) Net income per share - basic (in dollars per share) Earnings Per Share, Basic Raw materials Inventory, Raw Materials, Gross Contract liabilities Contract liabilities Contract with Customer, Liability, Current Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Long-term debt Net long-term debt Long-Term Debt, Excluding Current Maturities Cost of revenue: Cost of Revenue Award Type Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Thereafter Finite-Lived Intangible Asset, Expected Amortization, After Year Four Finite-Lived Intangible Asset, Expected Amortization, After Year Four Product and Service [Axis] Product and Service [Axis] Revenue, Description Of Timing, 13 To 24 Months Revenue, Description Of Timing, 13 To 24 Months [Member] Revenue, Description Of Timing, 13 To 24 Months Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Contracting services private-sector Contracting services private-sector [Member] Contracting services private-sector Common Stock Common Stock [Member] Energy Services Energy Services Energy Services Energy Services Segment [Member] Energy Services Segment Fair Value Measurement [Domain] Fair Value Measurement [Domain] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Accrual for holdback payment related to a business combination Business Combination, Accrued Consideration Business Combination, Accrued Consideration Surety bond expiration period Surety Bond Expiration Period Surety Bond Expiration Period Amortization expense Intangible Asset, Finite-Lived, after Accumulated Amortization, Estimated Amortization Expense, Fiscal Year Maturity [Abstract] Stock-based compensation expense APIC, Share-Based Payment Arrangement, Recognition and Exercise Equity Awards Adjustments Equity Awards Adjustments [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Number of businesses acquired Business Combination, Number of Businesses Acquired Other Other [Member] Other Total liabilities and stockholders' equity  Liabilities and Equity Eliminations And Reconciling Items Eliminations And Reconciling Items [Member] Eliminations And Reconciling Items Employee Stock Option Share-Based Payment Arrangement, Option [Member] Fair value, balance sheet grouping [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Other Notes Notes Payable, Other Payables [Member] Oregon Supplier of Aggregates, Asphalt, Contracting and Paving Services Oregon Supplier of Aggregates, Asphalt, Contracting and Paving Services [Member] Oregon Supplier of Aggregates, Asphalt, Contracting and Paving Services Investments used to satisfy nonqualified benefit plans obligations Life Insurance, Corporate or Bank Owned, Amount Initial accounting incomplete, adjustment, intangibles Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Schedule of Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] Tabular List, Table Tabular List [Table Text Block] Other (expense) income Other Nonoperating Income (Expense) Parent Parent [Member] 2029 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three Remainder of 2026 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year Name Awards Close in Time to MNPI Disclosures, Individual Name Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Noncurrent assets: Assets, Noncurrent [Abstract] Other notes due on January 1, 2061 Other Notes Due 2061 [Member] Other Notes Due 2061 Receivables, net Receivables, Net, Current Adjustment to Compensation: Adjustment to Compensation [Axis] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest paid, net Interest Paid, Excluding Capitalized Interest, Operating Activity Capital expenditures Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Pension and postretirement benefit plan contributions Payment for Pension and Other Postretirement Benefits Trade Accounts Receivable Trade Accounts Receivable [Member] Credit Facility [Axis] Credit Facility [Axis] Background Restructuring and Related Activities Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Total assets measured at fair value Assets, Fair Value Disclosure Name Measure Name Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] Fair value, measurements [Domain] Fair Value Hierarchy and NAV [Domain] Long-term debt outstanding [Line Items] Debt Instrument [Line Items] Other current assets Increase (Decrease) in Other Current Assets Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Seasonality of operations Seasonality Of Operations [Policy Text Block] Seasonality Of Operations Business combination, consideration transferred Business Combination, Consideration Transferred Other Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and Cash Equivalent Amount of surety bonds outstanding Amount of surety bonds outstanding Amount of surety bonds outstanding related to construction contracts and reclamation obligations. Long-term debt maturities Long-Term Debt, Fiscal Year Maturity [Abstract] Company Selected Measure Amount Company Selected Measure Amount Depreciation, depletion and amortization Depreciation, depletion and amortization Depreciation, Depletion and Amortization Entity Address, Address Line Two Entity Address, Address Line Two Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts and Financing Receivables [Table] Net unrealized (loss) gain on investments Life Insurance, Corporate or Bank Owned, Change in Value Strata Ready-Mix Plant Operations Strata Ready-Mix Plant Operations [Member] Strata Ready-Mix Plant Operations Current assets: Assets, Current [Abstract] Consolidation and Elimination [Domain] Consolidation and Elimination [Domain] Consolidation and Elimination [Domain] Non-PEO NEO Non-PEO NEO [Member] Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Right-of-use assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Income tax expense Income Tax Expense (Benefit) Term loan B agreement due on March 8, 2032 5.74% Term Loan Agreement Due 2032 [Member] 5.74% Term Loan Agreement Due 2032 Award Timing Method Award Timing Method [Text Block] Principles of consolidation Consolidation, Policy [Policy Text Block] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Deferred tax liability acquired Business Combination, Recognized Liability Assumed, Deferred Tax Liability Pension and postretirement benefit plan net periodic benefit cost Pension and Other Postretirement Benefits Expense (Reversal of Expense), Noncash New Accounting Standards Accounting Standards Update and Change in Accounting Principle [Text Block] Net income Net income Net (loss) income Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] Restatement Determination Date: Restatement Determination Date [Axis] Schedule of Changes in Contract Assets and Liabilities Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Senior notes due on May 1, 2031 7.75% Senior Notes Due 2031 [Member] 7.75% Senior Notes Due 2031 Initial accounting incomplete, adjustment, property, plant, and equipment Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment Revenue: Revenues [Abstract] Number of reportable segments aligned with geographic areas Number Of Reportable Segments Aligned With Geographic Areas Number Of Reportable Segments Aligned With Geographic Areas Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]