1.0.0.3 false CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands false 1 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 2 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 3 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 3 Cash flows from operating activities: 1 us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 4 Net income (loss) 2 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true -311943000 -311943 false false 2 true true -915245000 -915245 false false 3 true true 345262000 345262 false false No definition available. No authoritative reference available. false 5 Adjustments to reconcile net income (loss) to net cash provided by operating activities: 2 us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 6 Impairments and other valuation losses 3 us-gaap_AssetImpairmentCharges us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 806039000 806039 false false 2 false true 2259687000 2259687 false false 3 false true 2138000 2138 false false No definition available. No authoritative reference available. false 7 Depreciation, depletion and amortization 3 us-gaap_ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 265699000 265699 false false 2 false true 547404000 547404 false false 3 false true 461791000 461791 false false No definition available. No authoritative reference available. false 8 Asset retirement obligation 3 xec_AssetRetirementObligationIncludingPluggingAndAbandonment xec false debit duration monetary Accretion expense of asset retirement obligations related to oil and gas producing activities, including gains or losses of... false false false false false false false false false 1 false true 12313000 12313 false false 2 false true 8796000 8796 false false 3 false true 8937000 8937 false false Accretion expense of asset retirement obligations related to oil and gas producing activities, including gains or losses of plugging and abandonments. No authoritative reference available. false 9 Deferred income taxes 3 us-gaap_DeferredIncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -164760000 -164760 false false 2 false true -602593000 -602593 false false 3 false true 166813000 166813 false false No definition available. No authoritative reference available. false 10 Stock compensation, net 3 us-gaap_ShareBasedCompensation us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 9254000 9254 false false 2 false true 10090000 10090 false false 3 false true 10772000 10772 false false No definition available. No authoritative reference available. false 11 Derivative instruments, net 3 us-gaap_UnrealizedGainLossOnDerivatives us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 14453000 14453 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. No authoritative reference available. false 12 Gain on liquidation of equity investees 3 us-gaap_GainLossOnSaleOfEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false true -39000 -39 false false 3 false true -3015000 -3015 false false No definition available. No authoritative reference available. false 13 Changes in non-current assets and liabilities 3 us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 8948000 8948 false false 2 false true 119562000 119562 false false 3 false true -47000 -47 false false No definition available. No authoritative reference available. false 14 Other, net 3 us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 18478000 18478 false false 2 false true 15557000 15557 false false 3 false true 509000 509 false false No definition available. No authoritative reference available. false 15 Changes in operating assets and liabilities 3 us-gaap_IncreaseDecreaseInOperatingCapitalAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 16 (Increase) decrease in receivables, net 4 us-gaap_IncreaseDecreaseInReceivables us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 29881000 29881 false false 2 false true 56245000 56245 false false 3 false true -7777000 -7777 false false No definition available. No authoritative reference available. false 17 (Increase) decrease in oil and gas well equipment and supplies and other current assets 4 us-gaap_IncreaseDecreaseInOtherOperatingAssets us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 49894000 49894 false false 2 false true -155222000 -155222 false false 3 false true -33917000 -33917 false false No definition available. No authoritative reference available. false 18 Increase (decrease) in accounts payable and accrued liabilities 4 us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -63079000 -63079 false false 2 false true 23246000 23246 false false 3 false true 43214000 43214 false false No definition available. No authoritative reference available. false 19 Net cash provided by operating activities 3 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true 675177000 675177 false false 2 false true 1367488000 1367488 false false 3 false true 994680000 994680 false false No definition available. No authoritative reference available. true 20 Cash flows from investing activities: 1 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 21 Oil and gas expenditures 2 us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -535308000 -535308 false false 2 false true -1594775000 -1594775 false false 3 false true -1021456000 -1021456 false false No definition available. No authoritative reference available. false 22 Sales of oil and gas and other assets 2 us-gaap_ProceedsFromSaleOfProductiveAssets us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 119735000 119735 false false 2 false true 39096000 39096 false false 3 false true 177195000 177195 false false No definition available. No authoritative reference available. false 23 Distributions received from equity investees 2 xec_DistributionsReceivedFromEquityInvestees xec false debit duration monetary This item represents disclosure of the amount of distributions received that constitute a return of investment from... false false false false false false false false false 1 false false 0 0 false false 2 false true 39000 39 false false 3 false true 3015000 3015 false false This item represents disclosure of the amount of distributions received that constitute a return of investment from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations; these investments are accounted for under the equity method of accounting. No authoritative reference available. false 24 Purchases of short-term investments 2 us-gaap_PaymentsToAcquireShortTermInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -16000000 -16000 false false No definition available. No authoritative reference available. false 25 Sales of short-term investments 2 us-gaap_ProceedsFromSaleOfShortTermInvestments us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3328000 3328 false false 2 false true 10679000 10679 false false 3 false true 1424000 1424 false false No definition available. No authoritative reference available. false 26 Other expenditures 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -31849000 -31849 false false 2 false true -51757000 -51757 false false 3 false true -19574000 -19574 false false No definition available. No authoritative reference available. false 27 Net cash used by investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -444094000 -444094 false false 2 false true -1596718000 -1596718 false false 3 false true -875396000 -875396 false false No definition available. No authoritative reference available. true 28 Cash flows from financing activities: 1 us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 29 Net Increase (decrease) in bank debt 2 xec_ProceedsFromRepaymentsOfBankDebt xec false debit duration monetary The net cash inflow (outflow) in aggregate bank debt due to repayments and proceeds from additional borrowings. false false false false false false false false false 1 false true -195000000 -195000 false false 2 false true 220000000 220000 false false 3 false true -95000000 -95000 false false The net cash inflow (outflow) in aggregate bank debt due to repayments and proceeds from additional borrowings. No authoritative reference available. false 30 Increase in other long-term debt 2 us-gaap_ProceedsFromIssuanceOfOtherLongTermDebt us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 350000000 350000 false false No definition available. No authoritative reference available. false 31 Decrease in other long-term debt 2 us-gaap_RepaymentsOfOtherLongTermDebt us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false true -105550000 -105550 false false 3 false true -204360000 -204360 false false No definition available. No authoritative reference available. false 32 Financing costs incurred 2 us-gaap_PaymentsOfFinancingCosts us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -18001000 -18001 false false 2 false true -158000 -158 false false 3 false true -6113000 -6113 false false No definition available. No authoritative reference available. false 33 Treasury stock acquired and retired 2 us-gaap_PaymentsForRepurchaseOfCommonStock us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -42266000 -42266 false false No definition available. No authoritative reference available. false 34 Dividends paid 2 us-gaap_PaymentsOfDividendsCommonStock us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -20172000 -20172 false false 2 false true -20040000 -20040 false false 3 false true -13429000 -13429 false false No definition available. No authoritative reference available. false 35 Issuance of common stock and other 2 us-gaap_ProceedsFromIssuanceOrSaleOfEquity us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3421000 3421 false false 2 false true 13141000 13141 false false 3 false true 9886000 9886 false false No definition available. No authoritative reference available. false 36 Net cash provided by (used in) financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -229752000 -229752 false false 2 false true 107393000 107393 false false 3 false true -1282000 -1282 false false No definition available. No authoritative reference available. true 37 Net change in cash and cash equivalents 1 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true 1331000 1331 false false 2 false true -121837000 -121837 false false 3 false true 118002000 118002 false false No definition available. No authoritative reference available. true 38 Cash and cash equivalents at beginning of period 1 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false true false false 1 false true 1213000 1213 false false 2 false true 123050000 123050 false false 3 false true 5048000 5048 false false No definition available. No authoritative reference available. false 39 Cash and cash equivalents at end of period 1 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false true false 1 true true 2544000 2544 false false 2 true true 1213000 1213 false false 3 true true 123050000 123050 false false No definition available. No authoritative reference available. false false 3 37 false Thousands UnKnown UnKnown false true