Entity Central Index Key Document And Company Information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Well Known Seasoned Issuer Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Entity Filer Category Entity Filer Category Entity Common Stock Shares Outstanding Entity Common Stock Shares Outstanding Entity Public Float Entity Public Float Income Statement [Abstract] Net Sales Sales Revenue Goods Net Freight and delivery revenues Shipping And Handling Revenue Total revenues Sales Revenue Net Cost of sales Cost Of Goods Sold Freight and delivery costs Shipping Handling And Transportation Costs Total cost of revenues Cost Of Goods And Services Sold Gross Profit Gross Profit Selling, general and administrative expenses Selling General And Administrative Expense Acquisition-related expenses Business Combination Acquisition Related Costs Other operating expenses and (income), net Other Operating Income Expense Net Earnings from Operations Operating Income Loss Interest expense Interest Expense Other nonoperating (income) and expenses, net Other Nonoperating Income Expense Earnings before income tax (benefit) expense Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Income tax (benefit) expense Income Tax Expense Benefit Consolidated net earnings Profit Loss Less: Net earnings attributable to noncontrolling interests Net Income Loss Attributable To Noncontrolling Interest Net Earnings Attributable to Martin Marietta Net Income Loss Net Earnings Attributable to Martin Marietta Per Common Share (see Note A) Earnings Per Share [Abstract] Basic attributable to common shareholders Earnings Per Share Basic Diluted attributable to common shareholders Earnings Per Share Diluted Weighted-Average Common Shares Outstanding Weighted Average Number Of Shares Outstanding [Abstract] Basic Weighted Average Number Of Shares Outstanding Basic Diluted Weighted Average Number Of Diluted Shares Outstanding Other comprehensive income loss net periodic pension cost due to special plan termination benefits net of tax. Statement Of Income And Comprehensive Income [Abstract] Consolidated Net Earnings Other comprehensive (loss) earnings, net of tax: Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract] Defined benefit pension and postretirement plans: Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Period Increase Decrease [Abstract] Net loss arising during period, net of tax of $(2,625), $(19,734) and $(4,530), respectively Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax Amortization of prior service credit, net of tax of $(547), $(617) and $(731), respectively Other Comprehensive Income Loss Amortization Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax Amortization of actuarial loss, net of tax of $5,271, $4,437 and $6,551, respectively Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax Amount recognized in net periodic pension cost due to settlement, net of tax of $8, $44 and $0 respectively Other Comprehensive Income Loss Finalization Of Pension And Non Pension Postretirement Plan Valuation Net Of Tax Amount recognized in net periodic pension cost due to special plan termination benefits, net of tax of $0, $293 and $811, respectively Other Comprehensive Income Loss Net Periodic Pension Cost Due To Special Plan Termination Benefits Net Of Tax Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax Foreign currency translation gain (loss) Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax Amortization of terminated value of forward starting interest rate swap agreements into interest expense, net of tax of $571, $541 and $509, respectively Other Comprehensive Income Loss Reclassification Adjustment From A O C I On Derivatives Net Of Tax Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income Loss Net Of Tax Consolidated comprehensive earnings Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest Less: Comprehensive earnings attributable to noncontrolling interests Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest Comprehensive Earnings Attributable to Martin Marietta Comprehensive Income Net Of Tax Other comprehensive income net periodic pension cost due to special plan termination benefits tax. Net loss arising during period, tax Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax Amortization of prior service credit, tax Other Comprehensive Income Loss Amortization Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax Amortization of actuarial loss, tax Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax Amount recognized in net periodic pension cost due to settlement, tax Other Comprehensive Income Finalization Of Pension And Non Pension Postretirement Plan Valuation Tax Amount recognized in net periodic pension cost due to special plan termination benefits, tax Other Comprehensive Income Net Periodic Pension Cost Due To Special Plan Termination Benefits Tax Amortization of terminated value of forward starting interest rate swap agreements into interest expense, tax Other Comprehensive Income Loss Reclassification Adjustment From A O C I On Derivatives Tax Intangible assets operating permits net. Statement Of Financial Position [Abstract] Current Assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Accounts receivable, net Accounts And Other Receivables Net Current Inventories, net Inventory Net Other current assets Other Assets Current Total Current Assets Assets Current Property, plant and equipment, net Property Plant And Equipment Net Goodwill Goodwill Operating permits, net Intangible Assets Operating Permits Net Other intangibles, net Other Intangible Assets Net Other noncurrent assets Other Assets Noncurrent Total Assets Assets Current Liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued salaries, benefits and payroll taxes Employee Related Liabilities Current Pension and postretirement benefits Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Current Accrued insurance and other taxes Accrual For Taxes Other Than Income Taxes Current Current maturities of long-term debt Long Term Debt Current Other current liabilities Other Liabilities Current Total Current Liabilities Liabilities Current Long-term debt Long Term Debt Noncurrent Pension, postretirement and postemployment benefits Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent Deferred income taxes, net Deferred Tax Liabilities Noncurrent Other noncurrent liabilities Other Liabilities Noncurrent Total Liabilities Liabilities Equity: Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract] Common stock ($0.01 par value; 100,000,000 shares authorized; 62,873,000 and 63,176,000 shares outstanding at December 31, 2017 and 2016, respectively) Common Stock Value Preferred stock ($0.01 par value; 10,000,000 shares authorized; no shares outstanding) Preferred Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated other comprehensive loss Accumulated Other Comprehensive Income Loss Net Of Tax Retained earnings Retained Earnings Accumulated Deficit Total Shareholders’ Equity Stockholders Equity Noncontrolling interests Minority Interest Total Equity Stockholders Equity Including Portion Attributable To Noncontrolling Interest Total Liabilities and Equity Liabilities And Stockholders Equity Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares outstanding Common Stock Shares Outstanding Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, shares outstanding Preferred Stock Shares Outstanding Payments of deferred acquisition consideration. Statement Of Cash Flows [Abstract] Cash Flows from Operating Activities: Net Cash Provided By Used In Operating Activities [Abstract] Consolidated net earnings Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest Adjustments to reconcile consolidated net earnings 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 Depreciation Depletion And Amortization Stock-based compensation expense Share Based Compensation (Gain) Loss on divestitures and sales of assets Gain Loss On Disposition Of Assets Deferred income taxes, net Deferred Income Tax Expense Benefit Other items, net Other Noncash Income Expense Changes in operating assets and liabilities, net of effects of acquisitions and divestitures: Increase Decrease In Operating Capital [Abstract] Accounts receivable, net Increase Decrease In Accounts Receivable Inventories, net Increase Decrease In Inventories Accounts payable Increase Decrease In Accounts Payable Trade Other assets and liabilities, net Increase Decrease In Other Operating Capital Net Net Cash Provided by Operating Activities Net Cash Provided By Used In Operating Activities Cash Flows from Investing Activities: Net Cash Provided By Used In Investing Activities [Abstract] Additions to property, plant and equipment Payments To Acquire Property Plant And Equipment Acquisitions Payments To Acquire Businesses Gross Cash received in acquisition Cash Acquired From Acquisition Proceeds from divestitures and sales of assets Proceeds From Sales Of Business Affiliate And Productive Assets Payment of railcar construction advances Repayments Of Advances For Construction Reimbursement of railcar construction advances Proceeds From Advances For Construction Repayments from affiliate Proceeds From Collection Of Advance To Affiliate Net Cash (Used for) Provided by Investing Activities Net Cash Provided By Used In Investing Activities Cash Flows from Financing Activities: Net Cash Provided By Used In Financing Activities [Abstract] Borrowings of long-term debt Proceeds From Issuance Of Long Term Debt Repayments of long-term debt Repayments Of Long Term Debt Payments of deferred acquisition consideration Payments Of Deferred Acquisition Consideration Debt issuance costs Payments Of Debt Issuance Costs Change in bank overdraft Proceeds From Repayments Of Bank Overdrafts Payments on capital lease obligations Repayments Of Long Term Capital Lease Obligations Dividends paid Payments Of Dividends Common Stock Distributions to owners of noncontrolling interest Payments Of Dividends Minority Interest Contributions by noncontrolling interest to joint venture Proceeds From Minority Shareholders Repurchase of common stock Payments For Repurchase Of Common Stock Proceeds from exercise of stock options Proceeds From Stock Options Exercised Shares withheld for employees' income tax obligations Payments Related To Tax Withholding For Share Based Compensation Net Cash Provided by (Used for) 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, beginning of year Cash and Cash Equivalents, end of year Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-In Capital Additional Paid In Capital [Member] Accumulated Other Comprehensive (Loss) Earnings Accumulated Other Comprehensive Income [Member] Retained Earnings Retained Earnings [Member] Total Shareholders' Equity Parent [Member] Noncontrolling Interests Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Beginning Balance Beginning Balance (in shares) Consolidated net earnings Other comprehensive (loss) earnings Dividends declared ($1.60 in 2015 and $1.64 in 2016 & 1.72 in 2017 per common share) Dividends Common Stock Cash Issuances of common stock for stock award plans Stock Issued During Period Value Share Based Compensation Issuances of common stock for stock award plans (in shares) Stock Issued During Period Shares Share Based Compensation Shares withheld for employees' income tax obligations Adjustments Related To Tax Withholding For Share Based Compensation Repurchases of common stock Stock Repurchased During Period Value Repurchases of common stock, Shares Stock Repurchased During Period Shares Stock-based compensation expense Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Noncontrolling interest acquired from business combination Noncontrolling Interest Increase From Business Combination Purchase of subsidiary shares from noncontrolling interest Minority Interest Decrease From Redemptions Distributions to owners of noncontrolling interests Minority Interest Decrease From Distributions To Noncontrolling Interest Holders Contribution from owners of noncontrolling interest Noncontrolling Interest Increase From Subsidiary Equity Issuance Ending Balance Ending Balance (in shares) Cash dividends declared per common share Common Stock Dividends Per Share Declared Accounting Policies [Abstract] Accounting Policies Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Text Block] Goodwill And Intangible Assets Disclosure [Abstract] Goodwill and Other Intangible Assets Goodwill And Intangible Assets Disclosure [Text Block] Business Combinations [Abstract] Business Combinations Business Combination Disclosure [Text Block] Receivables [Abstract] Accounts Receivable, Net Loans Notes Trade And Other Receivables Disclosure [Text Block] Inventory Disclosure [Abstract] Inventories, Net Inventory Disclosure [Text Block] Property Plant And Equipment [Abstract] Property, Plant and Equipment, Net Property Plant And Equipment Disclosure [Text Block] Debt Disclosure [Abstract] Long-Term Debt Debt Disclosure [Text Block] Financial instruments disclosure. Financial Instruments Disclosure [Abstract] Financial Instruments Financial Instruments Disclosure [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Compensation And Retirement Disclosure [Abstract] Retirement Plans, Postretirement and Postemployment Benefits Pension And Other Postretirement Benefits Disclosure [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Stock-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Leases [Abstract] Leases Leases Of Lessee Disclosure [Text Block] Equity [Abstract] Shareholders' Equity Stockholders Equity Note Disclosure [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Segment Reporting [Abstract]