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	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Non-qualified Supplemental Retirement Plan ("SERP")
Multiemployer Plans [Line Item]
Gains (losses), net	$ (253)	$ 806	$ 384	$ 1,374

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