Annual report pursuant to Section 13 and 15(d)

Leases (Narrative) (Details)

Leases (Narrative) (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Leases, Operating [Abstract]      
Number of real estate leases 46odfl_NumberOfRealEstateUnderOperatingLease    
Number Of Service Center Locations 222odfl_NumberOfServiceCenterLocations    
Aggregate expense under operating leases $ 16.5us-gaap_OperatingLeasesRentExpenseMinimumRentals $ 17.9us-gaap_OperatingLeasesRentExpenseMinimumRentals $ 19.1us-gaap_OperatingLeasesRentExpenseMinimumRentals