75000 - Document - Document and Entity Information link:presentationLink link:calculationLink link:definitionLink 75010 - Statement - Statements Of Net Assets Available For Benefits link:presentationLink link:calculationLink link:definitionLink 75020 - Statement - Statement Of Changes In Net Assets Available For Benefits link:presentationLink link:calculationLink link:definitionLink 75030 - Disclosure - Description of Plan link:presentationLink link:calculationLink link:definitionLink 75040 - Disclosure - Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 75050 - Disclosure - Fair Value Measurements link:presentationLink link:calculationLink link:definitionLink 75060 - Disclosure - Investment in Insurance Fund link:presentationLink link:calculationLink link:definitionLink 75070 - Disclosure - Exempt Party-in-interest Transactions link:presentationLink link:calculationLink link:definitionLink 75080 - Disclosure - Federal Income Tax Status link:presentationLink link:calculationLink link:definitionLink 75090 - Disclosure - Risks and Uncertainties link:presentationLink link:calculationLink link:definitionLink 75100 - Disclosure - Plan Termination link:presentationLink link:calculationLink link:definitionLink 75110 - Disclosure - Reconciliation of Financial Statements to Form 5500 link:presentationLink link:calculationLink link:definitionLink 75120 - Disclosure - Legal Proceedings link:presentationLink link:calculationLink link:definitionLink 75130 - Disclosure - Subsequent Events link:presentationLink link:calculationLink link:definitionLink 75140 - Disclosure - Schedule H, Line 4i - Schedule of Assets (Held At End Of Year) link:presentationLink link:calculationLink link:definitionLink 75150 - Disclosure - Schedule H, Line 4j - Schedule of Reportable Transactions link:presentationLink link:calculationLink link:definitionLink 75160 - Disclosure - Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 75170 - Disclosure - Description of Plan (Tables) link:presentationLink link:calculationLink link:definitionLink 75180 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 75190 - Disclosure - Reconciliation of Financial Statements to Form 5500 (Tables) link:presentationLink link:calculationLink link:definitionLink 75200 - Disclosure - Schedule H, Line 4i - Schedule of Assets (Held At End Of Year) (Tables) link:presentationLink link:calculationLink link:definitionLink 75210 - Disclosure - Schedule of Reportable Transactions (Tables) link:presentationLink link:calculationLink link:definitionLink 75220 - Disclosure - Description of Plan - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75230 - Disclosure - Description of Plan - Summary of Vesting in the Company's Contribution Portion of Participants' Accounts Plus Actual Earnings Thereon (Details) link:presentationLink link:calculationLink link:definitionLink 75240 - Disclosure - Description of Plan - Summary of Reconciliation of Change in Forfeited Non-vested Accounts (Details) link:presentationLink link:calculationLink link:definitionLink 75250 - Disclosure - Fair Value Measurements - Schedule of Fair Value Measurements (Details) link:presentationLink link:calculationLink link:definitionLink 75260 - Disclosure - Exempt Party-in-interest Transactions - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75270 - Disclosure - Reconciliation of Financial Statements to Form 5500 - Reconciliation of Net Assets Available for Benefits (Details) link:presentationLink link:calculationLink link:definitionLink 75280 - Disclosure - Reconciliation of Financial Statements to Form 5500 - Reconciliation of Increase in Net Assets (Details) link:presentationLink link:calculationLink link:definitionLink 75290 - Disclosure - Legal Proceedings - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75300 - Disclosure - Schedule H, Line 4i - Schedule of Assets (Held At End Of Year) (Details) link:presentationLink link:calculationLink link:definitionLink 75300 - Disclosure - Schedule H, Line 4i - Schedule of Assets (Held At End Of Year) (Details) [Default] link:presentationLink link:calculationLink link:definitionLink 75310 - Disclosure - Schedule H, Line 4j - Schedule of Reportable Transactions (Details) link:presentationLink link:calculationLink link:definitionLink 75310 - Disclosure - Schedule H, Line 4j - Schedule of Reportable Transactions (Details) [Default] link:presentationLink link:calculationLink link:definitionLink EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Benefits paid to participants EBP, Reconciliation to Form 5500, Change in Net Asset Available for Benefit, Current Period, Decrease from Deemed Distribution Current year deemed defaulted loans EBP, Receivable [Abstract] Receivables: Fair Value, Inputs, Level 2 [Member] Level 2 EBP, Related Party and Party-in-Interest Transactions [Line Items] Document Fiscal Period Focus EBP, Employer Contribution, Receivable Employer contributions EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Forfeitures used to reduce Company matching contributions Forfeitures used to reduce Company matching contributions Employee Benefit Plan Note Receivable From Participant Interest Rate Employee benefit plan note receivable from participant interest rate. Employee benefit plan note receivable from participant interest rate EBP, Form 5500 Caption, Net Income (Loss) Increase in net assets available for benefits per the Form 5500 Participant contributions description Employee Benefit Plan Participant Contributions Description Employee Benefit Plan Participant Contributions Description. EBP, Investment in insurance fund. EBP, Investment in Insurance Fund [Abstract] EBP, Tax Status [Abstract] EBP, Forfeited Nonvested Account Forfeited non-vested accounts at beginning of year Forfeited non-vested accounts at end of year EBP, Description of Plan [Text Block] Description of Plan Employee Benefit Plan Net Assets Available For Benefits [Abstract] Employee Benefit Plan Net Assets Available For Benefits. NET ASSETS AVAILABLE FOR BENEFITS: EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants Investment, Identifier [Axis] EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative fees EBP, Description of Plan [Line Items] EBP, Employer Contribution, Matching Percentage Employer matching contribution percentage EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Identity of Party Involved EBP, Investment, Fair Value and NAV [Abstract] EBP, Accounting Policy [Line Items] EBP, Schedule of Asset Held for Investment [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Schedule of Reportable Transaction [Abstract] EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Maximum notes receivable from participants Common Collective Trust [Member] Collective Trust Funds Amendment Flag EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash, Total Employer contributions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] DEDUCTIONS FROM NET ASSETS ATTRIBUTED TO: EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Minimum notes receivable from participants EBP, Payment to Participant [Policy Text Block] Payment of Benefits EBP, Investment, Excluding Plan Interest in Master Trust, Fair and Contract Value Total investments Employee Benefit Plans Vesting Percentage Four Years Of Credited Service Employer contribution vesting percentage for participants with four years of credited service. Vested Percentage, 4 Years of Service EBP, Participant Contribution, Receivable Participant contributions EBP, Schedule of Asset Held for Investment [Line Items] Fair Value Hierarchy and NAV [Axis] EBP, Description of Investment Including Maturity Date, Rate of Interest, Collateral, Par, or Maturity Value EBP, Investment, Current Value, Type [Extensible Enumeration] Investment Type [Axis] Document Type Entity Central Index Key EBP, Self-Directed Brokerage Account [Member] Self-directed Brokerage Accounts Subsequent Event Type [Domain] EBP, Investment [Policy Text Block] Investment Valuation and Income Recognition Employee Benefit Plan Forfeited Nonvested Account During Period Employee Benefit Plan Forfeited Nonvested Account During Period. Forfeitures EBP, Reconciliation to Form 5500, Change in Net Asset Available for Benefit, Prior Period, Increase from Deemed Distribution Prior year deemed defaulted loans - paid through termination EBP, Subsequent Event [Table] EBP, Accounting Policy [Table] EBP, Subsequent Event [Abstract] EBP, Basis of Accounting [Policy Text Block] Basis of Accounting EBP, Schedule of Reportable Transaction [Line Items] EBP, Schedule of Reportable Transaction [Table] EBP, Description of Plan [Table] EBP, Employer, Common Stock [Member] Old Dominion Freight Line, Inc. Common Stock Common Stock Subsequent Event [Member] Subsequent Event EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment, Total Interest and dividend income Employee Benefit Plan Notes Receivable from Participants Interest Rate Description Employee Benefit Plan Notes Receivable from Participants Interest Rate Description. Employee benefit plan notes receivable from participants interest rate description Employee Benefit Plan Participant Loans Maturity Date Employee benefit plan participant loans maturity date. EBP, Asset Held for Investment, Participant Loans, Maturity Date EBP, Investment, Fair Value [Abstract] Investments, at fair value: EBP, Investment, Fair and Contract Value Total investments EBP, Form 5500 Caption, Net Assets Net assets available for benefits per the Form 5500 Net assets available for benefits per the Form 5500 EBP, Investment, Number of Shares Shares of common stock Minimum [Member] Minimum EBP, Related Party and Party-in-Interest Transactions [Text Block] Exempt Party-in-interest Transactions EBP, Change in Net Asset Available for Benefit, Increase Total additions Fair Value, Inputs, Level 3 [Member] Level 3 EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price EBP, Selling Price EBP, Reconciliation of Financial Statement to Form 5500 [Line Items] EBP, Expense [Policy Text Block] Administrative Expenses Employee Benefit Plan Reconciliation To Form 5500 Payment To Participant Decrease For Interest On Deemed Defaulted Loans Amount of decrease in net asset available for benefit for interest on deemed defaulted loans to reconcile the change in net asset available for benefit per financial statement to Form 5500 caption. Form 5500 is form provided by Department of the Treasury, Internal Revenue Service (IRS); Department of Labor (DOL), Employee Benefit Security Administration (EBSA); and Pension Benefit Guaranty Corporation (PBGC). Interest on deemed defaulted loans Document Information [Line Items] Investments Measured at NAV Fair Value Measured at Net Asset Value Per Share [Member] EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Participant contributions Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Level 1, 2 and 3 EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions: Elective deferrals percentage of compensation EBP, Participant Contribution, Automatic, Deferral Rate Automatic deferral percentage of compensation EBP, Current Value of Asset on Transaction Date EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Current Value EBP, Fully Benefit-Responsive Investment Contract [Text Block] Investment in Insurance Fund EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Legal proceedings. EBP, Legal Proceedings [Line Items] EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Ending Balance EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Beginning Balance EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Total Common stock Total investments, at fair value Total investments at fair value E B P Legal Proceedings Text Block Legal Proceedings The entire EBP disclosure for legal proceedings. EBP, Use of Estimate [Policy Text Block] Estimates Mutual Fund [Member] Mutual Funds Entity [Domain] EBP, Cost of Asset EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] EBP, Pooled Separate Account [Member] Pooled Separate Accounts EBP, Investment, Fair Value and NAV [Text Block] Fair Value Measurements EBP, Description of Plan and Accounting Change [Abstract] EBP, Reconciliation of Financial Statement to Form 5500 [Table Text Block] Reconciliation of Net Assets Available for Benefits and Increase in Net Assets EBP, Statement of Change in Net Asset Available for Benefit [Line Items] Statistical Measurement [Domain] EBP, Note Receivable from Participant Notes receivable from participants Document Period End Date EBP, Risk and Uncertainty [Table] Fair Value Hierarchy and NAV [Domain] EBP, Purchase Price EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Purchase Price EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Percentage of notes receivable from participants EBP, Related Party and Party-in-Interest Transactions [Table] Employee Benefit Plan Dividends Distributed As Cash Employee benefit plan dividends distributed as cash. Dividends distributed as cash EBP, Plan Termination [Text Block] Plan Termination EBP, Subsequent Event [Text Block] Subsequent Events Cover [Abstract] EBP, Forfeited Nonvested Account [Abstract] Investments [Domain] Employee Benefit Plans Vesting Percentage Five Years Of Credited Service Employer contribution vesting percentage for participants with five years of credited service. Vested Percentage, 5 Years of Service Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] EBP, Risk and Uncertainty [Abstract] Employee Benefit Plans Vesting Percentage Less Than Two Years Of Credited Service Employer contribution vesting percentage for participants with less than two years of credited service. Vested Percentage, Less than 2 Years of Service EBP, Net Asset Available for Benefit Net assets available for benefits Net assets available for benefits per financial statements Net assets available for benefits at beginning of period Net assets available for benefits at end of period EBP, Investment, Fair Value and NAV [Table Text Block] Schedule of Fair Value Measurements EBP, Schedule of Asset Held for Investment [Abstract] EBP, Investment in insurance fund. EBP, Investment in Insurance Fund [Table] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable from Participants EBP, Schedule of Asset Held for Investment [Table Text Block] Schedule H, Line 4i - Schedule of Assets (Held At End Of Year) EBP, Statement of Net Asset Available for Benefit [Table] Summary of Vesting in the Company's Contribution Portion of Participants' Accounts Plus Actual Earnings Thereon Summary of vesting in the company's contribution portion of participants' accounts plus actual earnings thereon. Document Fiscal Year Focus EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment, Total Net appreciation in fair value of investments Participant compensation matched percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage Employer matching contribution, percent of compensation EBP, Statement of Change in Net Asset Available for Benefit [Table] Summary of Reconciliation of Change in Forfeited Non-vested Accounts Summary of Reconciliation of Change in Forfeited Non-vested Accounts [Table Text Block] Summary of Reconciliation of Change in Forfeited Non-vested Accounts. EBP, Contribution [Policy Text Block] Contributions from Participants and Employer EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Percentage of pretax annual compensation participants may contribute each year EBP, Plan Number EBP, Investment, Fair Value and NAV [Line Items] Document Information [Table] Legal Entity [Axis] EBP, Plan Name EBP, Reconciliation to Form 5500, Net Asset Available for Benefit, Deemed Distribution Deemed defaulted loans Deemed defaulted loans EBP, Risk and Uncertainty [Line Items] EBP, Asset [Abstract] EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Total investment income Subsequent Event Type [Axis] EBP, Investment, Fair Value and NAV [Table] EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Rollover contributions Employee Benefit Plan Participant Contribution Automatic Deferral Rate Limit Percentage Employee Benefit Plan Participant Contribution Automatic Deferral Rate Limit Percentage. Elective maximum deferrals percentage of compensation EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Employee Benefit Plan Note Receivable from Participant Basis Spread on Variable Rate Percentage added to reference rate used to compute variable rate on notes receivable from participants in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee benefit plan note receivable from participant basis spread on variable rate Employee Benefit Plan Additional Aggregate Discretionary Matching Contribution Amount of increase in net asset available for benefit from discretionary cash contributions from employer of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Additional aggregate discretionary matching contribution awarded EBP, Subsequent Event [Line Items] EBP, Reconciliation of Financial Statement to Form 5500 [Table] Employee Benefit Plans Vesting Percentage Two Years Of Credited Service Employer contribution vesting percentage for participants with two years of credited service. Vested Percentage, 2 Years of Service EBP, Tax Status [Text Block] Federal Income Tax Status Maximum Maximum [Member] Statistical Measurement [Axis] EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Employee Benefit Plans Vesting Percentage Three Years Of Credited Service Employer contribution vesting percentage for participants with three years of credited service. Vested Percentage, 3 Years of Service Employee Benefit Plans Vesting Percentage Six Years Of Credited Service Employer contribution vesting percentage for participants with six years of credited service. Vested Percentage, 6 Years of Service Entity Registrant Name Settlement funds distributed Settlement funds distributed. Total receivables EBP, Receivable EBP, Asset Held for Investment, Participant Loan, Interest Rate Participant loan, interest rate EBP, Schedule of Reportable Transaction [Table Text Block] Schedule of Reportable Transactions Schedule H, Line 4j - Schedule of Reportable Transactions EBP, Reconciliation of Financial Statement to Form 5500 [Text Block] Reconciliation of Financial Statements to Form 5500 Employee Benefit Plan Schedule of Reportable Transaction [Text Block] Employee benefit plan schedule of reportable transaction. Schedule of Reportable Transactions Summary of Vesting in Contribution Portion of Participants" Accounts Plus Actual Earnings Thereon [Table Text Block] Summary of Vesting in Contribution Portion of Participants" Accounts Plus Actual Earnings Thereon. Summary of Vesting in Contribution Portion of Participants" Accounts Plus Actual Earnings Thereon EBP, Reconciliation of Financial Statement to Form 5500 [Abstract] EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Realized Gain (Loss) on Investment EBP, Net Gain or (Loss) EBP, Risk and Uncertainty [Text Block] Risks and Uncertainties EBP, Change in Net Asset Available for Benefit, Decrease Total deductions EBP, Legal proceedings. EBP, Legal Proceedings [Table] Fair Value, Inputs, Level 1 [Member] Level 1 EBP, Legal Proceedings [Abstract] EBP, Legal proceedings. EBP, Tax Status [Line Items] Entity Tax Identification Number EBP 002 [Member] EBP 002. EBP 002 EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Net increase Increase in net assets available for benefits per financial statements EBP, Tax Status [Table] EBP, Investment, Excluding Plan Interest in Master Trust, Contract Value Investment in insurance contract, at contract value EBP, Investment in insurance fund. EBP, Investment in Insurance Fund [Line Items] Old Dominion Freight Line, Inc. [Member] Institutional 500 Index Trust Unit Class C. Institutional Total International Stock Market Index Trust. Schwab. Old Dominion Freight Line, Inc. Capital Group [Member] Institutional 500 Index Trust Unit Class C [Member] Empower [Member] Vanguard. Vanguard [Member] MetWest. Schwab [Member] Kayne Anderson Rudnick [Member] Institutional Total International Stock Market Index Trust [Member] JP Morgan [Member] Empower. MetWest [Member] Jennison. Institutional Total International Stock Market Index Trust Unit Class C. American [Member] Russell [Member] Russell. Jennison [Member] Institutional Total International Stock Market Index Trust Unit Class C [Member] Institutional 500 Index Trust. Kayne Anderson Rudnick. JP Morgan. Capital Group. Institutional 500 Index Trust [Member] American.