Annual report pursuant to Section 13 and 15(d)

Income Taxes (Federal Operating Loss Carryforwards) (Details)

v2.4.1.9
Income Taxes (Federal Operating Loss Carryforwards) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Operating Loss Carryforwards [Line Items]  
Federal NOL carryforwards $ 247,513us-gaap_OperatingLossCarryforwards
Operating loss carryforwards, valuation allowance 171,907us-gaap_OperatingLossCarryforwardsValuationAllowance
2021-2023 [Member]  
Operating Loss Carryforwards [Line Items]  
Federal NOL carryforwards 111,415us-gaap_OperatingLossCarryforwards
/ us-gaap_TaxPeriodAxis
= cpe_TaxExpirationPeriod2Member
2024-2026 [Member]  
Operating Loss Carryforwards [Line Items]  
Federal NOL carryforwards 14,408us-gaap_OperatingLossCarryforwards
/ us-gaap_TaxPeriodAxis
= cpe_TaxExpirationPeriod3Member
2027-2029 [Member]  
Operating Loss Carryforwards [Line Items]  
Federal NOL carryforwards 41,379us-gaap_OperatingLossCarryforwards
/ us-gaap_TaxPeriodAxis
= cpe_TaxExpirationPeriod4Member
2030-2033 [Member]  
Operating Loss Carryforwards [Line Items]  
Federal NOL carryforwards $ 80,311us-gaap_OperatingLossCarryforwards
/ us-gaap_TaxPeriodAxis
= cpe_TaxExpirationPeriod5Member