ACCOUNTING POLICIES (Pension) (Details)	Jun. 30, 2013
Nonunion Defined Benefit Pension Plan
Nonunion Defined Benefit Pension, Supplemental Benefit, and Postretirement Health Plans
Period of estimate of future compensation rates used to establish the assumed rate of compensation increase	2 years

Represents the period of estimate of future compensation rates used to establish the assumed rate of compensation increase.

No definition available.

Name:	arcb_DefinedBenefitPlanAssumptionsRateOfCompensationIncreasePeriodOfEstimateOfFutureCompensationRates
Namespace Prefix:	arcb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration