Significant Accounting Policies	9 Months Ended
Sep. 30, 2014
Accounting Policies [Abstract]
Significant Accounting Policies	Note 1. Significant Accounting Policies Basis of Presentation The accompanying unaudited, interim condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and, in management’s opinion, contain all adjustments (consisting of normal recurring items) necessary for a fair presentation, in all material respects, of the financial position and results of operations for the periods presented. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. The preparation of condensed financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions. Such estimates and assumptions affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Our operating results are subject to seasonal trends; therefore, the results of operations for the interim period ended September 30, 2014 are not necessarily indicative of the results that may be expected for subsequent quarterly periods or the year ending December 31, 2014. The condensed financial statements should be read in conjunction with the financial statements and related notes, which appear in our Annual Report on Form 10-K for the year ended December 31, 2013. There have been no significant changes in the accounting principles and policies, long-term contracts or estimates inherent in the preparation of the condensed financial statements of Old Dominion Freight Line, Inc. as previously described in our Annual Report on Form 10-K for the year ended December 31, 2013. Unless the context requires otherwise, references in these Notes to “Old Dominion,” the “Company,” “we,” “us” and “our” refer to Old Dominion Freight Line, Inc. Fair Values of Financial Instruments The carrying values of financial instruments in current assets and current liabilities approximate their fair value due to the short maturities of these instruments. The carrying value of our long-term debt was $183.9 million and $191.4 million at September 30, 2014 and December 31, 2013, respectively. The estimated fair value of our total long-term debt was $187.6 million and $196.5 million at September 30, 2014 and December 31, 2013, respectively. The fair value measurement of our senior notes was determined using market interest rates for similar issuances of private debt. Since this methodology is based upon indicative market interest rates, the measurement is categorized as Level 2 under the three-level fair value hierarchy as established by the Financial Accounting Standards Board (the “FASB”). The fair value of our other long-term debt approximates carrying value due to the variable interest rates within these instruments. Earnings Per Share Earnings per share is computed using the weighted average number of common shares outstanding during the period. Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update ("ASU") 2014-09, Revenue from Contracts with Customers. This ASU supersedes the previous revenue recognition requirements in Accounting Standards Codification ("ASC") 605—Revenue Recognition and most industry-specific guidance throughout the ASC. The core principle within this ASU is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This ASU is effective for fiscal years beginning after December 15, 2016, and for interim periods within those fiscal years. The Company continues to assess the method of application and impact, if any, of the adoption of ASU 2014-09 on its financial position, results of operations and cash flows. In June 2014, the FASB issued ASU 2014-12, Compensation—Stock Compensation: Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. The amendments of this ASU require that a performance target, which affects vesting and could be achieved after the requisite service period, be treated as a performance condition under the existing guidance in ASC Topic 718. This ASU is effective for annual and interim periods beginning after December 15, 2015, and early adoption is permitted. The Company does not believe the adoption of ASU 2014-12 will have an impact on its financial position, results of operations or cash flows.

Note 1. Significant Accounting Policies

Basis of Presentation

The accompanying unaudited, interim condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and, in management’s opinion, contain all adjustments (consisting of normal recurring items) necessary for a fair presentation, in all material respects, of the financial position and results of operations for the periods presented. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements.

The preparation of condensed financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions. Such estimates and assumptions affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Our operating results are subject to seasonal trends; therefore, the results of operations for the interim period ended September 30, 2014 are not necessarily indicative of the results that may be expected for subsequent quarterly periods or the year ending December 31, 2014.

The condensed financial statements should be read in conjunction with the financial statements and related notes, which appear in our Annual Report on Form 10-K for the year ended December 31, 2013. There have been no significant changes in the accounting principles and policies, long-term contracts or estimates inherent in the preparation of the condensed financial statements of Old Dominion Freight Line, Inc. as previously described in our Annual Report on Form 10-K for the year ended December 31, 2013.

Unless the context requires otherwise, references in these Notes to “Old Dominion,” the “Company,” “we,” “us” and “our” refer to Old Dominion Freight Line, Inc.

Fair Values of Financial Instruments

The carrying values of financial instruments in current assets and current liabilities approximate their fair value due to the short maturities of these instruments. The carrying value of our long-term debt was $183.9 million and $191.4 million at September 30, 2014 and December 31, 2013, respectively. The estimated fair value of our total long-term debt was $187.6 million and $196.5 million at September 30, 2014 and December 31, 2013, respectively. The fair value measurement of our senior notes was determined using market interest rates for similar issuances of private debt. Since this methodology is based upon indicative market interest rates, the measurement is categorized as Level 2 under the three-level fair value hierarchy as established by the Financial Accounting Standards Board (the “FASB”). The fair value of our other long-term debt approximates carrying value due to the variable interest rates within these instruments.

Earnings Per Share

Earnings per share is computed using the weighted average number of common shares outstanding during the period.

Recent Accounting Pronouncements

In May 2014, the FASB issued Accounting Standards Update ("ASU") 2014-09, Revenue from Contracts with Customers. This ASU supersedes the previous revenue recognition requirements in Accounting Standards Codification ("ASC") 605—Revenue Recognition and most industry-specific guidance throughout the ASC. The core principle within this ASU is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This ASU is effective for fiscal years beginning after December 15, 2016, and for interim periods within those fiscal years. The Company continues to assess the method of application and impact, if any, of the adoption of ASU 2014-09 on its financial position, results of operations and cash flows.

In June 2014, the FASB issued ASU 2014-12, Compensation—Stock Compensation: Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. The amendments of this ASU require that a performance target, which affects vesting and could be achieved after the requisite service period, be treated as a performance condition under the existing guidance in ASC Topic 718. This ASU is effective for annual and interim periods beginning after December 15, 2015, and early adoption is permitted. The Company does not believe the adoption of ASU 2014-12 will have an impact on its financial position, results of operations or cash flows.