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v3.20.4

Share-Based Compensation - Summary of Activity for PBRSUs for Employees (Parenthetical) (Details) - PBRSUs [Member] | 12 Months Ended
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Dec. 31, 2020
Minimum [Member] |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
Grants as percentage of target award | 0.00%
Maximum [Member] |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
Grants as percentage of target award | 200.00%

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- Definition Share-based compensation arrangement by share-based payment award equity instruments other than options, grants as a percentage of the target award in a period. + References No definition available. + Details
Name: | odfl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPercentageOfTargetAwardInPeriod
Namespace Prefix: | odfl_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_AwardTypeAxis=odfl_PerformanceBasedRestrictedStockUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |