REVENUES - Payment Terms (Details)	9 Months Ended
Sep. 30, 2020
Minimum
Revenue satisfaction period	30 days
Maximum
Revenue satisfaction period	60 days

The satisfaction period of revenue remaining performance obligation.

No definition available.

Name:	res_RevenueRemainingPerformanceObligationSatisfactionPeriod
Namespace Prefix:	res_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration