XML 66 R56.htm IDEA: XBRL DOCUMENT v3.20.2

STOCKHOLDERS' EQUITY (Reclass) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Unrecognized Net Periodic Benefit Credit (cost)
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax	$ 352	$ (9,115)
Tax benefit (expense)	(91)	1,324
Total, net of tax	261	(7,791)
Unrecognized Net Periodic Benefit Credit (cost) | Nonunion Defined Benefit Pension Plan
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax		(7,300)
Amortization of net actuarial gain (loss)
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax	441	(1,005)
Amortization of net actuarial gain (loss) | Nonunion Defined Benefit Pension Plan
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax		(300)
Amortization of prior service credit
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax		25
Pension settlement expense, including termination expense
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax	$ (89)	(8,135)
Pension settlement expense, including termination expense | Nonunion Defined Benefit Pension Plan
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax		(8,100)
Pension termination expense | Nonunion Defined Benefit Pension Plan
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax		(4,000)
Tax benefit (expense)		$ 0

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_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount before tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580

+ Details

Name:	us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121640130&loc=d3e1436-108581

+ Details

Name:	us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e640-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 17A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL34724391-108580

+ Details

Name:	us-gaap_ReclassificationFromAociCurrentPeriodTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
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_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=arcb_AccumulatedDefinedBenefitPlansAdjustmentPensionSettlementExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=arcb_AccumulatedDefinedBenefitPlansAdjustmentPensionTerminationExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: