Annual report pursuant to Section 13 and 15(d)

Income Taxes Income Taxes (Narrative) (Details)

v2.4.1.9
Income Taxes Income Taxes (Narrative) (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Income Tax Disclosure [Abstract]  
Deferred Tax Assets, Tax Credit Carryforwards $ 4.3us-gaap_DeferredTaxAssetsTaxCreditCarryforwards
Tax Credit Carryforward, Expiration Date Minimum 5odfl_TaxCarryforwardNumberOfYearsMinimum
Tax Credit Carryforward, Expiration Date Maximum 15odfl_TaxCarryforwardNumberOfYearsMaximum