Annual report pursuant to Section 13 and 15(d)

Borrowings (Senior secured revolving credit facility ) (Details)

v2.4.1.9
Borrowings (Senior secured revolving credit facility ) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Oct. 08, 2014
Mar. 11, 2014
Dec. 31, 2013
Line of Credit Facility [Line Items]        
Senior secured revolving credit facility $ 35,000us-gaap_LongTermLineOfCredit     $ 22,000us-gaap_LongTermLineOfCredit
Senior Secured Revolving Credit Facility [Member]        
Line of Credit Facility [Line Items]        
Maximum borrowing capacity     500,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
 
Current borrowing capacity   250,000us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
   
Senior secured revolving credit facility 35,000us-gaap_LongTermLineOfCredit
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
    22,000us-gaap_LongTermLineOfCredit
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
Interest rate at period end (as a percent) 1.91%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
     
Unused capacity, commitment fee (as a percent) 0.50%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
     
Remaining borrowing capacity $ 215,000us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
     
Senior Secured Revolving Credit Facility [Member] | Minimum [Member]        
Line of Credit Facility [Line Items]        
Basis Spread on LIBOR (as a percent) 1.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
     
Senior Secured Revolving Credit Facility [Member] | Maximum [Member]        
Line of Credit Facility [Line Items]        
Basis Spread on LIBOR (as a percent) 2.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= cpe_SeniorSecuredRevolvingCreditFacilityMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember