XML 47 R33.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Financial instruments (Details) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2024 USD ($) | Dec. 31, 2023 USD ($)
Fair value disclosure |  |
Outstanding withdrawal liability | $ 19,200 |
Accrued expenses |  |
Fair value disclosure |  |
Outstanding withdrawal liability | 700 |
Carrying Value |  |
Fair value disclosure |  |
Financial instruments | 231,393 | $ 248,340
Fair Value | Level 2 |  |
Fair value disclosure |  |
Financial instruments | 227,119 | 245,369
Credit Facility | Carrying Value |  |
Fair value disclosure |  |
Financial instruments | 50,000 | 50,000
Credit Facility | Fair Value | Level 2 |  |
Fair value disclosure |  |
Financial instruments | 50,000 | 50,000
Notes payable | Carrying Value |  |
Fair value disclosure |  |
Financial instruments | 162,171 | 178,938
Notes payable | Fair Value | Level 2 |  |
Fair value disclosure |  |
Financial instruments | 159,385 | 177,149
New England Pension Fund withdrawal liability | Carrying Value |  |
Fair value disclosure |  |
Financial instruments | 19,222 | 19,402
New England Pension Fund withdrawal liability | Fair Value | Level 2 |  |
Fair value disclosure |  |
Financial instruments | $ 17,734 | $ 18,220
Measurement input | 0.056 | 0.053
Financial Instrument, Measurement Input | us-gaap:MeasurementInputDiscountRateMember | us-gaap:MeasurementInputDiscountRateMember

X
- Definition Value of input used to measure financial instrument. + References No definition available. + Details
Name: | arcb_FinancialInstrumentMeasurementInput
Namespace Prefix: | arcb_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Indicates measurement input for financial instrument. + References No definition available. + Details
Name: | arcb_FinancialInstrumentMeasurementInputExtensibleEnumeration
Namespace Prefix: | arcb_
Data Type: | enum2:enumerationSetItemType
Balance Type: | na
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 No definition available. + Details
Name: | us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities. + References No definition available. + Details
Name: | us-gaap_FinancialLiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of the obligation recognized by withdrawing from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References No definition available. + Details
Name: | us-gaap_MultiemployerPlansWithdrawalObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_AccruedLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=arcb_NewEnglandPensionFundWithdrawalLiabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |