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

- Definition

Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

+ References

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-Name Accounting Standards Codification
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-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash outflow for pension benefit. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree. Excludes other postretirement benefit.

+ References

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-Subparagraph (g)
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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PENSION AND RETIREMENT PLANS LIABILITIES - SERP (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
PENSION AND RETIREMENT PLANS LIABILITIES
Unrealized gain/loss due to change in fair value of SERP liabilities		$ (195)	$ (17,254)	$ (585)
Non-qualified Supplemental Retirement Plan ("SERP")
PENSION AND RETIREMENT PLANS LIABILITIES
Fair value of plan assets	$ 25,100		25,100		$ 24,200
Trading gains (losses), net	(305)	(2,600)	903	(4,100)
SERP Liabilities	21,900		21,900		$ 23,100
Unrealized gain/loss due to change in fair value of SERP liabilities	$ 262	$ 2,500	(1,000)	$ 3,900
Retirement Income Plan
PENSION AND RETIREMENT PLANS LIABILITIES
Cash contribution			$ 5,400