EMPLOYEE BENEFIT PLAN - Trading results related to SERP (Details 1) (Supplemental Retirement Plan ('SERP'), USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Supplemental Retirement Plan ('SERP')
Multiemployer Plans [Line Item]
Gains (losses), net	$ 680	$ (735)	$ 860	$ (613)

The element represents gain loss on defined benefit plan assets.

No definition available.

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