2.4.0.8029 - Disclosure - Summary of Significant Accounting Policies (Details Textual)truefalseIn Thousands, except Share data, unless otherwise specifiedfalse1false USDfalsefalse$Context_3ME__30-Jun-2013http://www.sec.gov/CIK0000086264duration2013-04-01T00:00:002013-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$Context_3ME__30-Jun-2012http://www.sec.gov/CIK0000086264duration2012-04-01T00:00:002012-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$Context_6ME__30-Jun-2013http://www.sec.gov/CIK0000086264duration2013-01-01T00:00:002013-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0PartnershipStandardhttp://www.cng.com/20130630Partnershipcrbo0pureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false USDfalsefalse$Context_6ME__30-Jun-2012http://www.sec.gov/CIK0000086264duration2012-01-01T00:00:002012-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Average Sales Price and Production Costs Per Unit of Production [Line Items]2false 2crbo_NumberOfPartnershipscrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse4242falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerRepresents the number of partnerships which have been consolidated for financial statement presentation purposes.No definition available.false256Number of consolidated partnerships3false 2crbo_OilAndGasOperationsConversionRatioGasToOilcrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse66falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:pureItemTypepureRepresents the conversion ratio of thousand cubic feet of natural gas to barrels of oil.No definition available.false0Gas to oil conversion ratio (thousand cubic feet of natural gas per barrel of oil)4false 2crbo_PercentageOfDiscountFactorForPresentValueOfFutureNetRevenuesFromProvedOilAndGasReservescrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.100.10falsefalsefalse4falsefalsefalse00falsefalsefalsenum:percentItemTypepureRepresents the discount rate applied to estimated future net revenues from proved reserves to derive the capitalized costs of oil and gas properties, under the full cost method of accounting.No definition available.false0Percentage of discount factor applied to estimated future net revenues from proved oil and gas reserves5false 2us-gaap_ImpairmentOfOilAndGasPropertiesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00  USD$falsefalsefalse2truefalsefalse99090009909USD$falsetruefalse3falsefalsefalse00  USD$falsefalsefalse4truefalsefalse1540700015407USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -Section 35 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=28370743&loc=d3e66150-109466 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2921-110230 false2Non-cash impairment expense6false 2us-gaap_CostMethodInvestmentsAdditionalInformationus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00The cost method of accounting is used for investments in affiliates in which the Company has less than a 20% of the voting interests of a corporate affiliate or less than a 5% interest of a partnership or limited liability company and does not have significant influence.falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringThis serves as a place to record data that is not specified elsewhere in the taxonomy but is useful for readers of the financial statements as it relates to the details of cost method investments.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 325 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596 false0Cost method investments, additional information7false 2us-gaap_EquityMethodInvestmentAdditionalInformationus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00If the Company holds between 20% and 50% of the voting interest in non-consolidated corporate affiliates or greater than 5% of a partnership or limited liability company and exercises significant influence or control, the equity method of accounting is used to account for the investment.falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringThis serves as a place to record data that is not required by accounting literature but is useful for readers of the financial statements as it relates to the details of an equity method investment in common stock. Such information may include the amount of change for a change in ownership (equity) percentage in a given period and the amount and type of the consideration given or received in relation to the change in ownership.No definition available.false0Equity method investment, additional information8false 2us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmountus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse2.72.7falsefalsefalse2truefalsefalse4.94.9falsefalsefalse3truefalsefalse27000002700000.0falsefalsefalse4truefalsefalse49000004900000.0falsefalsefalsexbrli:sharesItemTypesharesSecurities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 false1Anti-dilutive common stock equivalents excluded from calculation9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5false truefalseContext_6ME__30-Jun-2013_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxis_OilReservesMemberhttp://www.sec.gov/CIK0000086264duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseOil [Member]us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_OilReservesMemberus-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxisexplicitMemberPrice_Per_BOEStandardhttp://www.cng.com/20130630Price_Per_BOEcrbo0nanafalse0Oil [Member]10true 3us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Average Sales Price and Production Costs Per Unit of Production [Line Items]11false 4crbo_AverageSalesPricePerUnitcrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse91.6091.60falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:decimalItemTypedecimalThe revenues derived from sales of oil or gas in each geographic area during the reporting period divided by the number of barrels of oil produced or thousands of cubic feet of gas produced.No definition available.false256Average sales price per unit12false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse6false truefalseContext_6ME__30-Jun-2013_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxis_NaturalGasReservesMemberhttp://www.sec.gov/CIK0000086264duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseNatural Gas [Member]us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_NaturalGasReservesMemberus-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxisexplicitMemberPrice_Per_McfStandardhttp://www.cng.com/20130630Price_Per_Mcfcrbo0nanafalse0Natural Gas [Member]13true 3us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Average Sales Price and Production Costs Per Unit of Production [Line Items]14false 4crbo_AverageSalesPricePerUnitcrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse3.423.42falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:decimalItemTypedecimalThe revenues derived from sales of oil or gas in each geographic area during the reporting period divided by the number of barrels of oil produced or thousands of cubic feet of gas produced.No definition available.false256Average sales price per unit15false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse7false truefalseContext_6ME__30-Jun-2013_LegalEntityAxis_SubsidiariesMemberhttp://www.sec.gov/CIK0000086264duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseNytis USA [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_SubsidiariesMemberdei_LegalEntityAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0Nytis USA [Member]16true 4crbo_SummaryOfSignificantAccountingPoliciesTextualAbstractcrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Summary of Significant Accounting Policies (Textual)17false 5us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactionsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse1.001.00falsefalsefalse4falsefalsefalse00falsefalsefalsenum:percentItemTypepurePercentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.No definition available.false0Percentage of ownership interest in the subsidiary18false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse8false truefalseContext_6ME__30-Jun-2013_LegalEntityAxis_NytisLlcMemberhttp://www.sec.gov/CIK0000086264duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseNytis LLC [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicrbo_NytisLlcMemberdei_LegalEntityAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0Nytis LLC [Member]19true 4crbo_SummaryOfSignificantAccountingPoliciesTextualAbstractcrbo_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Summary of Significant Accounting Policies (Textual)20false 5us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactionsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.990.99falsefalsefalse4falsefalsefalse00falsefalsefalsenum:percentItemTypepurePercentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.No definition available.false0Percentage of ownership interest in the subsidiaryfalseSummary of Significant Accounting Policies (Details Textual) (USD $)ThousandsNoRoundingUnKnownUnKnowntruefalsefalseSheethttp://www.cng.com/role/SummaryofSignificantAccountingPoliciesDetailsTextual420