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EMPLOYEE BENEFIT PLANS - Plan summary (Details) | 12 Months Ended
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Dec. 31, 2022
Postretirement Health Benefit Plan |
Postretirement benefit plans |
Unrecognized prior service credit, amortization period | 9 years

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- Definition The period over which the unrecognized prior service cost (credit) is being amortized. + References No definition available. + Details
Name: | arcb_DefinedBenefitPlanUnrecognizedPriorServiceCreditAmortizationPeriod
Namespace Prefix: | arcb_
Data Type: | xbrli:durationItemType
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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_DefinedBenefitPostretirementHealthCoverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |