XML 111 R94.htm IDEA: XBRL DOCUMENT
v3.25.0.1

EMPLOYEE BENEFIT PLANS - Multiemployer Plans (Details) - Asset-Based $ in Thousands |  |  |  |  |  | 3 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Aug. 01, 2024 | Jan. 31, 2024 | Aug. 01, 2023 | Jan. 31, 2023 | Aug. 01, 2022 | Sep. 30, 2018 USD ($) | Jun. 30, 2018 USD ($) | Dec. 31, 2024 USD ($) plan | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Sep. 30, 2024 | Sep. 30, 2023 | Jan. 01, 2023 | Jan. 01, 2022
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum funded percentage of plans in green zone |  |  |  |  |  |  |  | 80.00% |  |  |  |  |  |
New England Teamsters Pension Fund | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Actuarially certified projected funded percentage of multiemployer pension plan |  |  |  |  |  |  |  |  |  |  | 65.00% | 65.00% |  |
Pension Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of multiemployer plans to which ABF Freight currently contributes | plan |  |  |  |  |  |  |  | 25 |  |  |  |  |  |
Maximum funded percentage of plans in yellow zone |  |  |  |  |  |  |  | 80.00% |  |  |  |  |  |
Maximum funded percentage of plans in red zone |  |  |  |  |  |  |  | 65.00% |  |  |  |  |  |
Maximum projected time to insolvency for plans in "critical and declining" status |  |  |  |  |  |  |  | 14 years |  |  |  |  |  |
Maximum projected time to insolvency for plans in "critical and declining" status if additional criteria apply |  |  |  |  |  |  |  | 19 years |  |  |  |  |  |
Threshold ratio of inactive to active participants for greater insolvency period to determine "critical and declining" status |  |  |  |  |  |  |  | 2 |  |  |  |  |  |
Threshold funded percentage for greater insolvency period to determine "critical and declining" status |  |  |  |  |  |  |  | 80.00% |  |  |  |  |  |
Percentage of contributions to the multiemployer pension plans that are in critical and declining status |  |  |  |  |  |  |  | 4.00% |  |  |  |  |  |
Percentage of contributions to the multiemployer pension plans that are in critical status |  |  |  |  |  |  |  | 54.00% |  |  |  |  |  |
Percentage of contributions to the multiemployer pension plans that are in endangered status |  |  |  |  |  |  |  | 0.00% |  |  |  |  |  |
Total multiemployer pension contributions paid |  |  |  |  |  |  |  | $ 157,892 | $ 162,484 | $ 154,558 |  |  |  |
Pension Plans | Central States Pension Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer pension contributions paid, individually significant |  |  |  |  |  |  |  | $ 75,004 | $ 77,708 | $ 75,306 |  |  |  |
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period |  |  |  |  |  |  |  |  | 5.00% | 5.00% |  |  |  |
Percentage of contributions to multiemployer pension plan |  |  |  |  |  |  |  | 50.00% | 50.00% | 50.00% |  |  |  |
Actuarially certified projected funded percentage of multiemployer pension plan |  |  |  |  |  |  |  |  |  |  |  |  | 98.50% | 14.50%
Pension Plans | Central States Pension Plan | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Actuarially certified projected funded percentage of multiemployer pension plan |  |  |  |  |  |  |  |  |  |  |  |  | 80.00% |
Pension Plans | Western Conference Of Teamsters Pension Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer pension contributions paid, individually significant |  |  |  |  |  |  |  | $ 27,701 | $ 29,540 | $ 28,051 |  |  |  |
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period |  |  |  |  |  |  |  |  | 5.00% | 5.00% |  |  |  |
Pension Plans | Central Pennsylvania Teamsters Defined Benefit Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer pension contributions paid, individually significant |  |  |  |  |  |  |  | 15,261 | $ 15,540 | $ 14,421 |  |  |  |
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period |  |  |  |  |  |  |  |  | 5.00% | 5.00% |  |  |  |
Pension Plans | I. B. of T. Union Local No. 710 Pension Fund |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer pension contributions paid, individually significant |  |  |  |  |  |  |  | 11,560 | $ 10,676 | $ 9,838 |  |  |  |
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period |  | 5.00% |  | 5.00% |  |  |  |  |  |  |  |  |  |
Pension Plans | New England Teamsters Pension Fund |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer pension contributions paid, individually significant |  |  |  |  |  |  |  | 4,548 | 4,636 | 4,449 |  |  |  |
Contributions to multiemployer plans related to pension fund withdrawal liability |  |  |  |  |  |  |  | 1,600 | 1,600 | 1,600 |  |  |  |
Multiemployer pension fund withdrawal liability charge (pre-tax) |  |  |  |  |  |  | $ 37,900 |  |  |  |  |  |  |
Initial lump sum payment of withdrawal liability |  |  |  |  |  | $ 15,100 |  |  |  |  |  |  |  |
Withdrawal liability monthly payments period (in years) |  |  |  |  |  | 17 years |  |  |  |  |  |  |  |
Pension Plans | All other plans in the aggregate |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer pension contributions paid, individually insignificant |  |  |  |  |  |  |  | $ 23,818 | 24,384 | 22,493 |  |  |  |
Pension Plans | Multiemployer pension plans receiving 1% to 2% ABF Freight's total multiemployer pension contributions | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of contributions to each individually insignificant multiemployer pension plan |  |  |  |  |  |  |  | 1.00% |  |  |  |  |  |
Pension Plans | Multiemployer pension plans receiving 1% to 2% ABF Freight's total multiemployer pension contributions | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of contributions to each individually insignificant multiemployer pension plan |  |  |  |  |  |  |  | 2.00% |  |  |  |  |  |
Health And Welfare Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Multiemployer Plans |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of multiemployer plans to which ABF Freight currently contributes | plan |  |  |  |  |  |  |  | 38 |  |  |  |  |  |
Total multiemployer pension contributions paid |  |  |  |  |  |  |  | $ 218,500 | $ 215,600 | $ 194,400 |  |  |  |
Percentage increase in contribution rate for time worked related to benefit costs | 3.70% |  | 5.40% |  | 4.30% |  |  |  |  |  |  |  |  |

X
- Definition Amount of pre-tax expenses associated with multiemployer pension fund withdrawal liability. + References No definition available. + Details
Name: | arcb_MultiemployerPensionFundWithdrawalLiabilityCharge
Namespace Prefix: | arcb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the projected funded percentage of a specified multiemployer pension plan. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlanFundedPercentage
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the maximum funded percentage of plans in the red zone. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansMaximumFundedPercentageOfPlansInRedZone
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maximum funded percentage of plans in the yellow zone. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansMaximumFundedPercentageOfPlansInYellowZone
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the minimum funded percentage of plans in the yellow zone. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansMinimumFundedPercentageOfPlansInGreenZone
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of the entity's contributions to multiemployer pension plans that are made to the specified plan. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansPercentageOfContributions
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of the entity's contributions to multiemployer pension plans that are made to plans in critical and declining status. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansPercentageOfContributionsToPlansInCriticalAndDecliningStatus
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of the entity's contributions to multiemployer pension plans that are made to plans in critical status. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansPercentageOfContributionsToPlansInCriticalStatus
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of the entity's contributions to multiemployer pension plans that are made to plans in endangered status. + References No definition available. + Details
Name: | arcb_MultiemployerPensionPlansPercentageOfContributionsToPlansInEndangeredStatus
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contributions made to multiemployer plan by employer related to pension fund withdrawal liability. + References No definition available. + Details
Name: | arcb_MultiemployerPlanContributionsByEmployerWithdrawalLiabilityCharge
Namespace Prefix: | arcb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents the threshold percentage of the entity's contributions to the plan relative to total contributions received by the plan, which was exceeded during the period, triggering disclosure of the plan year. + References No definition available. + Details
Name: | arcb_MultiemployerPlanMinimumPercentageThresholdOfContributionsToTotalPlanContributionsReceivedByPensionFund
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of the entity's contributions to each individually insignificant multiemployer pension plan. + References No definition available. + Details
Name: | arcb_MultiemployerPlanPensionInsignificantEmployerPercentageOfContributions
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The threshold funded percentage of plans, below which a higher maximum period for insolvency is used to determine "critical and declining" status. + References No definition available. + Details
Name: | arcb_MultiemployerPlansCriticalAndDecliningStatusThresholdFundedPercentageForGreaterInsolvencyPeriod
Namespace Prefix: | arcb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The threshold ratio of inactive participants to active participants, above which a higher maximum period for insolvency is used to determine "critical and declining" status. + References No definition available. + Details
Name: | arcb_MultiemployerPlansCriticalAndDecliningStatusThresholdRatioOfInactiveToActiveParticipantsForGreaterInsolvencyPeriod
Namespace Prefix: | arcb_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum period within which a plan in "critical and declining" status is expected to become insolvent, unless additional criteria relating to ratio of inactive to active participants or funded percentage are applicable. + References No definition available. + Details
Name: | arcb_MultiemployerPlansMaximumPeriodOfExpectedInsolvencyForCriticalAndDecliningStatus
Namespace Prefix: | arcb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum period within which a plan in "critical and declining" status is expected to become insolvent, if additional criteria relating to ratio of inactive to active participants or funded percentage are applicable. + References No definition available. + Details
Name: | arcb_MultiemployerPlansMaximumPeriodOfExpectedInsolvencyForCriticalAndDecliningStatusIfAdditionalCriteriaApply
Namespace Prefix: | arcb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The period of time over which monthly payments have to be made for withdrawal liability settlement for multiemployer plan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | arcb_MultiemployerPlansMonthlyPaymentsSettlementPeriod
Namespace Prefix: | arcb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of multiemployer plans to which the reporting entity currently contributes. + References No definition available. + Details
Name: | arcb_MultiemployerPlansNumber
Namespace Prefix: | arcb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash outflow for initial lumpsum payment of withdrawal liability from multiemployer plan. + References No definition available. + Details
Name: | arcb_MultiemployerPlansWithdrawalLiabilityInitialLumpsumPayment
Namespace Prefix: | arcb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Increase (decrease) in employer's contractual contribution rate to multiemployer plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-6 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-11 + Details
Name: | us-gaap_MultiemployerPlanContributionRateIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480547/715-80-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 35 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480606/715-80-35-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-11 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-9 + Details
Name: | us-gaap_MultiemployerPlanEmployerContributionCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost for employer contribution to multiemployer pension plan determined to be individually insignificant. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480547/715-80-55-8 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-9 + Details
Name: | us-gaap_MultiemployerPlanPensionInsignificantEmployerContributionCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost for employer contribution to multiemployer pension plan determined to be individually significant. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480547/715-80-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 + Details
Name: | us-gaap_MultiemployerPlanPensionSignificantEmployerContributionCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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 Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480547/715-80-55-8 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-6 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-6 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-11 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-11 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-11 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 35 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480606/715-80-35-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-11 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (e)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-5 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-9 Reference 19: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480576/715-80-50-6 + Details
Name: | us-gaap_MultiemployerPlansLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=arcb_AssetBasedSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_NewEnglandPensionFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_CentralStatesPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_WesternConferenceOfTeamstersPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_CentralPennsylvaniaTeamstersPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_Local710PensionFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_OtherPensionPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=arcb_MultiemployerPensionPlansReceivingSmallPercentagesOfTotalContributionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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