XML 46 R61.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Measurements--Nonrecurring Fair Value Measurements (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2012
drilling_rigs
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Nonrecurring Fair Value Measurements [Line Items]        
Number of drilling rigs no longer in service 3cpr_NumberofDrillingRigsNolongerinService      
Impairment losses   $ 0us-gaap_OtherAssetImpairmentCharges $ 3,490us-gaap_OtherAssetImpairmentCharges $ 2,000us-gaap_OtherAssetImpairmentCharges
Significant unobservable inputs (Level 3) [Member] | Nonrecurring fair value measurements [Member]        
Nonrecurring Fair Value Measurements [Line Items]        
Annual inflation rate   2.95%cpr_FairValueInputsAnnualInflationRate
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsNonrecurringMember		 2.95%cpr_FairValueInputsAnnualInflationRate
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsNonrecurringMember		  
Credit-adjusted risk-free interest rate   7.60%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsNonrecurringMember		 6.60%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsNonrecurringMember