EMPLOYEE BENEFIT PLAN - Trading results related to SERP (Details 1) (Non-qualified Supplemental Retirement Plan ("SERP"), USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Non-qualified Supplemental Retirement Plan ("SERP")
Multiemployer Plans [Line Item]
Gains (losses), net	$ 453	$ 46	$ 637	$ 568

This element represents the amount of trading gains (losses) of plan assets under the defined benefit plan.

No definition available.

Name:	res_DefinedBenefitPlanTradingGainsLosses
Namespace Prefix:	res_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration