XML 101 R88.htm IDEA: XBRL DOCUMENT v3.8.0.1

EMPLOYEE BENEFIT PLANS (Multiemployer Plans) (Details) $ in Thousands								12 Months Ended
	Aug. 01, 2017	Jan. 31, 2017	Aug. 01, 2016	Feb. 01, 2016	Jan. 31, 2016	Aug. 01, 2015	Feb. 01, 2015	Dec. 31, 2017 USD ($) $ / h plan	Jan. 31, 2017	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jan. 01, 2017	Jan. 01, 2016	Jan. 01, 2015
Multiemployer pension plans | Central States Pension Plan
Multiemployer Plans
Percentage of contributions to multiemployer pension plan								50.00%		50.00%	50.00%
Asset-Based
Multiemployer Plans
Maximum increase in combined contribution rates for health, welfare, and pension benefits each August 1 | $ / h								1.00
Minimum funded percentage of plans in green zone								80.00%
Asset-Based | Multiemployer 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								60.00%
Percentage of contributions to the multiemployer pension plans that are in critical status								1.00%
Percentage of contributions to the multiemployer pension plans that are in endangered status								6.00%
Total contributions to multiemployer plans								$ 158,416		$ 154,139	$ 151,898
Percentage increase in contribution rate for time worked related to benefit costs	1.70%		0.50%			1.20%
Maximum projected time to insolvency without legislative action								10 years
Asset-Based | Multiemployer pension plans | Central States Pension Plan
Multiemployer Plans
Total contributions to multiemployer plans								$ 78,230		$ 77,891	$ 77,491
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period										5.00%	5.00%
Approved increase in contribution (as a percent)	0.0		0.0			0.0
Actuarially certified projected funded percentage of multiemployer pension plan												37.80%	42.10%	47.90%
Asset-Based | Multiemployer pension plans | Western Conference of Teamsters Pension Plan
Multiemployer Plans
Total contributions to multiemployer plans								26,320		$ 25,075	$ 24,474
Approved increase in contribution (as a percent)	0.0		0.0			0.0
Asset-Based | Multiemployer pension plans | Central Pennsylvania Teamsters Pension Plan
Multiemployer Plans
Total contributions to multiemployer plans								13,391		13,381	13,147
Asset-Based | Multiemployer pension plans | Local 710 Pension Fund
Multiemployer Plans
Total contributions to multiemployer plans								10,054		9,670	10,020
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period		5.00%		5.00%	5.00%		5.00%		5.00%
Asset-Based | Multiemployer pension plans | All Other Pension Plans in Aggregate
Multiemployer Plans
Total contributions to multiemployer plans								$ 30,421		28,122	26,766
Asset-Based | Multiemployer pension plans | 707 Pension Fund
Multiemployer Plans
Percentage of contributions to multiemployer pension plan								1.00%
Asset-Based | Multiemployer pension plans | New York State Pension Fund
Multiemployer Plans
Percentage of contributions to multiemployer pension plan								2.00%
Asset-Based | Multiemployer health and welfare plans
Multiemployer Plans
Number of multiemployer plans to which ABF Freight currently contributes | plan								42
Total contributions to multiemployer plans								$ 162,200		$ 153,300	$ 144,700
Percentage increase in contribution rate for time worked related to benefit costs	3.90%		3.60%			5.80%
Asset-Based | Unionized employees concentration risk | Number of employees
Multiemployer Plans
Percentage of Asset-Based segment employees covered under collective bargaining agreement with the IBT								83.00%

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:	num: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:	num: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:	num: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:	num: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:	num: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:	num: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:	num: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:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Approved increase in employer's contractual contribution rate to multiemployer plan by Negotiating Committee of Plan.

+ References

No definition available.

+ Details

Name:	arcb_MultiemployerPlanApprovedContributionRateIncrease
Namespace Prefix:	arcb_
Data Type:	xbrli:pureItemType
Balance Type:	na
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:	num: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:	num: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 annual increase in the employer's combined health, welfare and pension benefit contribution rate for multiemployer plans.

+ References

No definition available.

+ Details

Name:	arcb_MultiemployerPlansMaximumContributionRateIncreaseDecrease
Namespace Prefix:	arcb_
Data Type:	xbrli:decimalItemType
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 maximum period within which a plan is expected to become insolvent without legislation action.

+ References

No definition available.

+ Details

Name:	arcb_MultiemployerPlansMaximumPeriodOfExpectedInsolvencyWithoutLegislativeAction
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

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450673-114947

+ Details

Name:	us-gaap_MultiemployerPlanContributionRateIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of contributions made to multiemployer plan by employer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

+ Details

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

X

- References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_MultiemployerPlanTypeAxis=us-gaap_MultiemployerPlansPensionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=arcb_CentralStatesPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=arcb_WesternConferenceofTeamstersPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=arcb_CentralPennsylvaniaTeamstersPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=arcb_Local710PensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=us-gaap_MultiemployerPlanIndividuallyInsignificantMultiemployerPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=arcb_Local707PensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanNameAxis=arcb_NewYorkStatePensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MultiemployerPlanTypeAxis=arcb_MultiemployerPlansHealthAndWelfareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_UnionizedEmployeesConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_NumberOfEmployeesTotalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: