Annual report pursuant to Section 13 and 15(d)

Long-Term Debt (Narrative) (Details)

v2.4.1.9
Long-Term Debt (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Debt Instrument [Line Items]    
Senior Notes 155,714,000us-gaap_SeniorNotes 191,429,000us-gaap_SeniorNotes
Minimum increments under the additional borrowings 25,000,000odfl_LineOfCreditFacilityMinimumIncrementsUnderAdditionalBorrowings  
Line of credit, outstanding 0us-gaap_LineOfCredit 0us-gaap_LineOfCredit
Minimum amount of dividends payable to shareholder as per credit agreement 40,000,000odfl_AmountOfRestrictedPaymentsLimitPerQuarter  
Amount Of Restricted Payments Limit Total 200,000,000odfl_AmountOfRestrictedPaymentsLimitTotal  
Stock Repurchased and Retired During Period, Value 5,532,000us-gaap_StockRepurchasedAndRetiredDuringPeriodValue  
Letter of Credit [Member]    
Debt Instrument [Line Items]    
Line of credit, outstanding 63,200,000us-gaap_LineOfCredit
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LetterOfCreditMember
57,700,000us-gaap_LineOfCredit
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LetterOfCreditMember
Senior Notes [Member]    
Debt Instrument [Line Items]    
Periodic principal payments 35,700,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
 
Fixed interest rate, minimum 4.00%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
 
Fixed interest rate, maximum 5.85%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
 
Effective average interest rate 4.87%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
4.99%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Minimum [Member]    
Debt Instrument [Line Items]    
Line Of Credit Facility Commitment Stated Fee Percentage 0.175%odfl_LineOfCreditFacilityCommitmentStatedFeePercentage
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
 
Maximum [Member]    
Debt Instrument [Line Items]    
Line Of Credit Facility Commitment Stated Fee Percentage 0.30%odfl_LineOfCreditFacilityCommitmentStatedFeePercentage
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
 
Letter of Credit [Member]    
Debt Instrument [Line Items]    
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases 150,000,000us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases
/ us-gaap_CreditFacilityAxis
= us-gaap_LetterOfCreditMember
 
Sweep Program [Member]    
Debt Instrument [Line Items]    
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases 20,000,000us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases
/ us-gaap_CreditFacilityAxis
= odfl_SweepProgramMember
 
Revolving Credit Facility [Member]    
Debt Instrument [Line Items]    
Maximum borrowing capacity 300,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
 
Current borrowing capacity 200,000,000us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
 
Interest Rate Spread added to LIBOR Rate 1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
 
Letter of credit fee 1.00%odfl_LetterOfCreditFeeInPercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
 
Commitment fee percentage 0.175%us-gaap_LineOfCreditFacilityCommitmentFeePercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
 
Facing fee on outstanding amount of letter of credit 0.125%odfl_AnnualRateOfFacingFeeOnDailyAverageAggregateAmountOfLetterOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
 
Revolving Credit Facility [Member] | Minimum [Member]    
Debt Instrument [Line Items]    
Interest Rate Spread added to LIBOR Rate 1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Letter of credit fee   1.00%odfl_LetterOfCreditFeeInPercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Commitment fee percentage   0.175%us-gaap_LineOfCreditFacilityCommitmentFeePercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Revolving Credit Facility [Member] | Maximum [Member]    
Debt Instrument [Line Items]    
Interest Rate Spread added to LIBOR Rate 1.875%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
1.10%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Letter of credit fee   1.125%odfl_LetterOfCreditFeeInPercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Commitment fee percentage   0.20%us-gaap_LineOfCreditFacilityCommitmentFeePercentage
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]    
Debt Instrument [Line Items]    
Interest Rate Spread added to LIBOR Rate 1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
 
Federal Funds Effective Swap Rate [Member] | Revolving Credit Facility [Member]    
Debt Instrument [Line Items]    
Interest Rate Spread added to LIBOR Rate 0.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_VariableRateAxis
= us-gaap_FederalFundsEffectiveSwapRateMember