-- None. No documentation exists for this element. -- Document and Entity Information Statement [Table] Statement [Table] Statement [Line Items] Statement 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 Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding CONSOLIDATED BALANCE SHEETS Assets [Abstract] ASSETS Assets, Current [Abstract] CURRENT ASSETS Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Short-term Investments Short-term investments Accounts Receivable, Net, Current Accounts receivable, less allowances (2019 – $6,655; 2018 – $7,380) Other Receivables, Net, Current Other accounts receivable, less allowances (2019 – $456; 2018 – $806) Prepaid Expense, Current Prepaid expenses This element represents carrying amount as of the balance sheet date of payments made in advance for income taxes, which will be charged against earnings within one year or the normal operating cycle, if longer. Also represents, carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Prepaid and Income Taxes Receivable, Current Prepaid and refundable income taxes Other Assets, Current Other Assets, Current TOTAL CURRENT ASSETS Property, Plant and Equipment, Gross [Abstract] PROPERTY, PLANT AND EQUIPMENT Gross amount as of the balance sheet date of real estate held for productive use and long-lived depreciable assets that include building structures held for productive use including any addition, improvement, or renovation to the structure, such as interior masonry, interior flooring, electrical, and plumbing. Land and Structures, Gross Land and structures Gross amount as of the balance sheet date of long-lived, depreciable assets used in the business of transporting freight, primarily tractors and trailers. Revenue Equipment, Gross Revenue equipment Gross amount at the balance sheet date for long-lived, depreciable assets used for providing services including assets commonly used in offices and other assets not otherwise defined in the taxonomy. Service, Office and Other Equipment, Gross Service, office, and other equipment Capitalized Computer Software, Gross Software Leasehold Improvements, Gross Leasehold improvements Property, Plant and Equipment, Gross TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less allowances for depreciation and amortization Property, Plant and Equipment, Net PROPERTY, PLANT AND EQUIPMENT, net Goodwill Goodwill GOODWILL Intangible Assets, Net (Excluding Goodwill) INTANGIBLE ASSETS, net Net Value Operating Lease, Right-of-Use Asset Operating right-of-use assets (long-term) Operating right of use assets OPERATING RIGHT OF USE ASSETS Deferred Income Tax Assets, Net DEFERRED INCOME TAXES Other Assets, Noncurrent OTHER LONG-TERM ASSETS Assets TOTAL ASSETS Liabilities and Equity [Abstract] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities, Current [Abstract] CURRENT LIABILITIES Accounts Payable, Current Accounts payable Accrued Income Taxes, Current Income taxes payable Accrued Liabilities, Current Accrued expenses Long-term Debt and Capital Lease Obligations, Current Current portion of long-term debt Less current portion Operating Lease, Liability, Current Operating lease liabilities (current) Current portion of operating lease liabilities Pension and Other Postretirement Defined Benefit Plans, Current Liabilities Current portion of pension and postretirement liabilities Liabilities, Current TOTAL CURRENT LIABILITIES Long-term Debt and Capital Lease Obligations LONG-TERM DEBT, less current portion Long-term debt, less current portion Operating Lease, Liability, Noncurrent Operating lease liabilities (long-term) OPERATING LEASE LIABILITIES, less current portion Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent PENSION AND POSTRETIREMENT LIABILITIES, less current portion Other Liabilities, Noncurrent OTHER LONG-TERM LIABILITIES Deferred Income Tax Liabilities, Net DEFERRED INCOME TAXES Stockholders' Equity Attributable to Parent [Abstract] STOCKHOLDERS' EQUITY Common Stock, Value, Issued Common stock, $0.01 par value, authorized 70,000,000 shares; issued 2019: 28,685,313 shares, 2018: 28,684,779 shares Additional Paid in Capital, Common Stock Additional paid-in capital Retained Earnings (Accumulated Deficit) Retained earnings Treasury Stock, Common, Value Treasury stock, at cost, 2019: 3,172,019 shares; 2018: 3,097,634 shares Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Stockholders' Equity Attributable to Parent Balances Balances Total after-tax amount TOTAL STOCKHOLDERS' EQUITY Liabilities and Equity TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY Allowance for Doubtful Accounts Receivable, Current Accounts receivable, allowances (in dollars) Allowance for Doubtful Other Receivables, Current Other accounts receivable, allowances (in dollars) Common Stock, Par or Stated Value Per Share Common stock, par value (in dollars per share) Common Stock, Shares Authorized Common stock, authorized shares Common Stock, Shares, Issued Common stock, issued shares Treasury Stock, Common, Shares Treasury stock, at cost, shares Treasury stock (in shares) CONSOLIDATED STATEMENTS OF OPERATIONS Revenue from Contract with Customer, Excluding Assessed Tax REVENUES Revenues Costs and Expenses OPERATING EXPENSES Total consolidated operating expenses Operating Income (Loss) OPERATING INCOME Nonoperating Income (Expense) [Abstract] OTHER INCOME (COSTS) Investment Income, Interest and Dividend Interest and dividend income Interest and Debt Expense Interest and other related financing costs Other Nonoperating Income (Expense) Other, net The aggregate amount of income or expense from ancillary business-related activities and interest and debt related expenses associated with nonoperating financing activities of the entity. Nonoperating Income (Expense) and Interest and Debt Expense TOTAL OTHER INCOME (COSTS) Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest INCOME BEFORE INCOME TAXES Income Tax Expense (Benefit) INCOME TAX PROVISION (BENEFIT) Net Income (Loss) Attributable to Parent NET INCOME NET INCOME Net income EARNINGS PER SHARE EARNINGS PER COMMON SHARE Earnings Per Share, Basic Basic (in dollars per share) Earnings per common share (in dollars per share) Earnings Per Share, Diluted Diluted (in dollars per share) Earnings per common share (in dollars per share) Weighted Average Number of Shares Outstanding, Diluted [Abstract] AVERAGE COMMON SHARES OUTSTANDING Diluted, denominator: Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Weighted-average shares Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) Adjusted weighted-average shares and assumed conversions Common Stock, Dividends, Per Share, Declared CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share) Dividends declared (in dollars per share) CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] OTHER COMPREHENSIVE INCOME, net of tax Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent [Abstract] Pension and other postretirement benefit plans: Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Net actuarial loss, net of tax of: (2019 – $230; 2018 – $899) Net of tax amount of the gain (loss) adjustment to other comprehensive income (loss) resulting from the settlement of the entity's defined benefit pension and other postretirement plans. Other Comprehensive Income (Loss), Finalization of Pension and Non-Pension Postretirement Plan Valuation, Settlements, Net of Tax Pension settlement expense, net of tax Pension settlement expense, net of tax of: (2019 – $349; 2018 – $168) Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract] Amortization of unrecognized net periodic benefit costs, net of tax of: (2019 – $100; 2018 – $219) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax Net actuarial loss Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), Net of Tax Prior service credit No definition available. Other Comprehensive Income (Loss), Derivatives and Foreign Currency, Net of Tax [Abstract] Interest rate swap and foreign currency translation: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Change in unrealized income (loss) on interest rate swap, net of tax of: (2019 – $118) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Change in unrealized income (loss) on interest rate swap, net of tax of: (2018 – $219) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Change in foreign currency translation, net of tax of: (2019 – $79; 2018 – $223) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other comprehensive income, net of tax OTHER COMPREHENSIVE INCOME, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent TOTAL COMPREHENSIVE INCOME Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax Net actuarial loss, tax expense (benefit) Tax effect of the gain (loss) adjustment to other comprehensive income (loss) resulting from the settlement of the entity's defined benefit pension and other postretirement plans. Other Comprehensive Income (Loss) Finalization of Pension and Non-Pension Postretirement Plan Valuation, Settlements, Tax Pension settlement expense, tax Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax Amortization of unrecognized net periodic benefit costs, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Change in unrealized income (loss) on interest rate swap, tax (benefit) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Change in unrealized income (loss) on interest rate swap, tax expense Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Change in foreign currency translation, tax expense (benefit) CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity Shares, Issued Balances (in shares) Balances (in shares) Cumulative Effect of New Accounting Principle in Period of Adoption Adjustment to beginning balance of accumulated other comprehensive loss for adoption of accounting standard Adjustments to beginning retained earnings for adoption of accounting standards Amount of stockholders' equity after the cumulative effect adjustment of a new accounting principle applied in the period of adoption. Stockholders' Equity, Adjusted Balance Adjusted Balances Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Issuance of common stock under share-based compensation plans Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Issuance of common stock under share-based compensation plans (in shares) Adjustments Related to Tax Withholding for Share-based Compensation Tax effect of share-based compensation plans Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Share-based compensation expense Treasury Stock, Value, Acquired, Cost Method Purchase of treasury stock Treasury Stock, Shares, Acquired Number of shares repurchased during the period Purchase of treasury stock (in shares) Dividends, Common Stock, Cash Dividends declared on common stock Dividend Amount CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities [Abstract] OPERATING ACTIVITIES Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by (used in) operating activities: Depreciation Depreciation and amortization Amortization of Intangible Assets Amortization of intangibles Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements Pension settlement expense Pension settlement expense, pre-tax Share-based Compensation. Share-based compensation expense Provision for Doubtful Accounts Provision for losses on accounts receivable Deferred Income Tax Expense (Benefit) Deferred income tax benefit Gain (Loss) on Disposition of Property Plant Equipment Gain on sale of property and equipment Gain on sale of property and equipment Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Receivables Receivables Increase (Decrease) in Prepaid Expense Prepaid expenses Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Income Taxes Income taxes Amount of increase (decrease) in multiemployer pension fund withdrawal liability. Increase (Decrease) in Multiemployer Pension Fund Withdrawal Liability Multiemployer pension fund withdrawal liability The increase (decrease) during the reporting period in the aggregate amount of obligations incurred but not paid, accrued expenses incurred but not paid, and other operating obligations not separately disclosed in the statement of cash flows. Increase (Decrease) in Accounts Payable Accrued Expenses and Other Liabilities Accounts payable, accrued expenses, and other liabilities Net Cash Provided by (Used in) Operating Activities NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] INVESTING ACTIVITIES Payments to Acquire Property, Plant, and Equipment Purchases of property, plant and equipment, net of financings Proceeds from Sale of Property, Plant, and Equipment Proceeds from sale of property and equipment Payments to Acquire Short-term Investments Purchases of short-term investments Proceeds from Sale of Short-term Investments Proceeds from sale of short-term investments Payments to Develop Software Capitalization of internally developed software Net Cash Provided by (Used in) Investing Activities NET CASH USED IN INVESTING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] FINANCING ACTIVITIES Repayments of Long-term Debt Payments on long-term debt Increase (Decrease) in Book Overdrafts Net change in book overdrafts Payments of Ordinary Dividends, Common Stock Payment of common stock dividends Payments for Repurchase of Common Stock Purchases of treasury stock Aggregate cost of shares repurchased during the period Payments Related to Tax Withholding for Share-based Compensation Payments for tax withheld on share-based compensation Net Cash Provided by (Used in) Financing Activities NET CASH USED IN FINANCING ACTIVITIES Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents CASH AND CASH EQUIVALENTS CASH AT END OF PERIOD Cash and cash equivalents at beginning of period Noncash Investing and Financing Items [Abstract] NONCASH INVESTING ACTIVITIES Fair Value of Assets Acquired Equipment financed Capital Expenditures Incurred but Not yet Paid Accruals for equipment received Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Lease liabilities arising from obtaining right-of-use assets ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS GOODWILL AND INTANGIBLE ASSETS Goodwill and Intangible Assets Disclosure [Text Block] GOODWILL AND INTANGIBLE ASSETS INCOME TAXES Income Tax Disclosure [Text Block] INCOME TAXES Leases The entire disclosure of information about leases. Lease Disclosure [Text Block] Leases LONG-TERM DEBT AND FINANCING ARRANGEMENTS Debt and Capital Leases Disclosures [Text Block] LONG-TERM DEBT AND FINANCING ARRANGEMENTS PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS Pension and Other Postretirement Benefits Disclosure [Text Block] PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS STOCKHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] STOCKHOLDERS' EQUITY SHARE-BASED COMPENSATION Disclosure of Compensation Related Costs, Share-based Payments [Text Block] SHARE-BASED COMPENSATION Earnings Per Share [Text Block] EARNINGS PER SHARE OPERATING SEGMENT DATA Segment Reporting Disclosure [Text Block] OPERATING SEGMENT DATA LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS Legal Matters and Contingencies [Text Block] LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS Basis of Accounting, Policy [Policy Text Block] Financial Statement Presentation Derivatives, Policy [Policy Text Block] Interest Rate Swap Derivative Instruments Lessee, Leases [Policy Text Block] Leases New Accounting Pronouncements, Policy [Policy Text Block] Accounting Pronouncements Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule components of cash and cash equivalents, short term investments, and restricted funds Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Schedule of fair value and carrying value disclosures of financial instruments Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of financial assets and liabilities measured at fair value on a recurring basis Tabular disclosure of intangibles assets, excluding goodwill, in total and by major class, including the gross carrying amount and accumulated amortization, if applicable. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Schedule of Finite and Indefinite Lived Intangible Assets [Table Text Block] Schedule of intangible assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of future amortization for intangible assets and acquired software Lease, Cost [Table Text Block] Schedule of components of lease expense Tabular disclosure of schedule of supplemental balance sheet information related to lease liabilities. Lease Balance Sheet Disclosure [Table Text Block] Schedule of supplemental balance sheet information related to lease liabilities Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of maturities of operating lease liabilities Schedule of Debt [Table Text Block] Schedule of long-term debt Tabular disclosure of contractually required rental payments on leases meeting the criteria for capitalization and maturities on long-term debt as of the date of the latest balance sheet date presented, in aggregate and for each of the five succeeding years, with separate deductions from the total for the amount of the imputed interest necessary to reduce the required rental payments and debt maturities to present value. Schedule of Maturities of Long Term Debt and Future Minimum Payments under Capital Leases [Table Text Block] Scheduled maturities of long-term debt obligations