<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.4.0.6</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>244</ContextCount>
  <ElementCount>220</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>74</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0010 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/BalanceSheet</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0015 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/BalanceSheetParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0020 - Statement - Condensed Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/StatementOfIncome</Role>
      <ShortName>Condensed Consolidated Statements of Operations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0030 - Statement - Condensed Consolidated Statements of Changes in Partners' Capital and Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/StatementOfChangesInPartnersCapitalAndStockholdersEquity</Role>
      <ShortName>Condensed Consolidated Statements of Changes in Partners' Capital and Stockholders' Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0035 - Statement - Condensed Consolidated Statements of Changes in Partners' Capital and Stockholders' Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/StatementOfChangesInPartnersCapitalAndStockholdersEquityParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Changes in Partners' Capital and Stockholders' Equity (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0040 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/CashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1010 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>1020 - Disclosure - Cash and Cash Equivalents</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureCashAndCashEquivalents</Role>
      <ShortName>Cash and Cash Equivalents</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>1030 - Disclosure - Restricted Funds</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureRestrictedFunds</Role>
      <ShortName>Restricted Funds</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>1040 - Disclosure - Joint Interest and Other Receivables</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureJointInterestAndOtherReceivables</Role>
      <ShortName>Joint Interest and Other Receivables</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>1050 - Disclosure - Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureInvestments</Role>
      <ShortName>Investments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>1060 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureFairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>1070 - Disclosure - Property, Plant, and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosurePropertyPlantAndEquipment</Role>
      <ShortName>Property, Plant, and Equipment</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>1080 - Disclosure - Long-term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureLongTermDebt</Role>
      <ShortName>Long-term Debt</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>1090 - Disclosure - Contractual Obligations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureContractualObligations</Role>
      <ShortName>Contractual Obligations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>1100 - Disclosure - Seismic and Exploration Expenses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSeismicAndExplorationExpenses</Role>
      <ShortName>Seismic and Exploration Expenses</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>1110 - Disclosure - Equity Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureEquityBasedCompensation</Role>
      <ShortName>Equity Based Compensation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>1120 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>1130 - Disclosure - Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureContingencies</Role>
      <ShortName>Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2010 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>3020 - Disclosure - Cash and Cash Equivalents (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureCashAndCashEquivalentsTables</Role>
      <ShortName>Cash and Cash Equivalents (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>3030 - Disclosure - Restricted Funds (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureRestrictedFundsTables</Role>
      <ShortName>Restricted Funds (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>3040 - Disclosure - Joint Interest and Other Receivables (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureJointInterestAndOtherReceivablesTables</Role>
      <ShortName>Joint Interest and Other Receivables (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>3050 - Disclosure - Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureInvestmentsTables</Role>
      <ShortName>Investments (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>3060 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>3070 - Disclosure - Property, Plant, and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosurePropertyPlantAndEquipmentTables</Role>
      <ShortName>Property, Plant, and Equipment (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>3080 - Disclosure - Long-term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureLongTermDebtTables</Role>
      <ShortName>Long-term Debt (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>3090 - Disclosure - Contractual Obligations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureContractualObligationsTables</Role>
      <ShortName>Contractual Obligations (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>3100 - Disclosure - Seismic and Exploration Expenses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSeismicAndExplorationExpensesTables</Role>
      <ShortName>Seismic and Exploration Expenses (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>3120 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>4010 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>4020 - Disclosure - Cash and Cash Equivalents (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureCashAndCashEquivalentsDetails</Role>
      <ShortName>Cash and Cash Equivalents (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>4030 - Disclosure - Restricted Funds (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureRestrictedFundsDetails</Role>
      <ShortName>Restricted Funds (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>4040 - Disclosure - Joint Interest and Other Receivables (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureJointInterestAndOtherReceivablesDetails</Role>
      <ShortName>Joint Interest and Other Receivables (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>4050 - Disclosure - Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureInvestmentsDetails</Role>
      <ShortName>Investments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>4060 - Disclosure - Fair Value Measurements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureFairValueMeasurementsDetails</Role>
      <ShortName>Fair Value Measurements (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>4070 - Disclosure - Property, Plant, and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosurePropertyPlantAndEquipmentDetails</Role>
      <ShortName>Property, Plant, and Equipment (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>4071 - Disclosure - Property, Plant, and Equipment (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosurePropertyPlantAndEquipmentDetails2</Role>
      <ShortName>Property, Plant, and Equipment (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>4080 - Disclosure - Long-term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureLongTermDebtDetails</Role>
      <ShortName>Long-term Debt (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>4081 - Disclosure - Long-term Debt (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureLongTermDebtDetails2</Role>
      <ShortName>Long-term Debt (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>4090 - Disclosure - Contractual Obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureContractualObligationsDetails</Role>
      <ShortName>Contractual Obligations (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>4100 - Disclosure - Seismic and Exploration Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSeismicAndExplorationExpensesDetails</Role>
      <ShortName>Seismic and Exploration Expenses (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>4110 - Disclosure - Equity Based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureEquityBasedCompensationDetails</Role>
      <ShortName>Equity Based Compensation (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>4120 - Disclosure - Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cobaltintl.com/role/DisclosureSegmentInformationDetails</Role>
      <ShortName>Segment Information (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Element cie_PercentageOfWorkingInterestAcquired had a mix of decimals attribute values: 2 4.</Log>
    <Log type="Info">Element us-gaap_CapitalizedExploratoryWellCostChargedToExpense had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">Element us-gaap_GainLossOnDispositionOfAssets had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">'Monetary' elements on report '4070 - Disclosure - Property, Plant, and Equipment (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4071 - Disclosure - Property, Plant, and Equipment (Details 2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4080 - Disclosure - Long-term Debt (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4081 - Disclosure - Long-term Debt (Details 2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 0010 - Statement - Condensed Consolidated Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Mar. 31, 2012'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2011'</Log>
    <Log type="Info">Process Flow-Through: 0015 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 0020 - Statement - Condensed Consolidated Statements of Operations</Log>
    <Log type="Info">	Process Flow-Through: Removing column '86 Months Ended
Dec. 31, 2012'</Log>
    <Log type="Info">Process Flow-Through: 0035 - Statement - Condensed Consolidated Statements of Changes in Partners' Capital and Stockholders' Equity (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 0040 - Statement - Condensed Consolidated Statements of Cash Flows</Log>
  </Logs>
  <InputFiles>
    <File>cie-20130331.xml</File>
    <File>cie-20130331.xsd</File>
    <File>cie-20130331_cal.xml</File>
    <File>cie-20130331_def.xml</File>
    <File>cie-20130331_lab.xml</File>
    <File>cie-20130331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
