| FAIR VALUE - Assets and Liabilities Fair Value Recurring Basis (Details 1) (USD $)In Thousands, unless otherwise specified
 | Mar. 31, 2015 | Dec. 31, 2014 | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | $ 231,727us-gaap_AvailableForSaleSecuritiesDebtSecurities |  | $ 231,754us-gaap_AvailableForSaleSecuritiesDebtSecurities | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment |  | 407,689us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment | 
      
        | Derivative Liabilities: |  |  |  | 
      
        | Derivative liabilities | 4,639us-gaap_DerivativeLiabilities |  | 4,328us-gaap_DerivativeLiabilities | 
      
        | Carrying Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 231,727us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 |  |  | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 |  |  | 
      
        | Derivative Liabilities: |  |  |  | 
      
        | Interest rate swaps, treated as hedges | 1,287us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 | [1] |  | 
      
        | Interest rate swapsand TBAs, not treated as hedges | 3,352us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 | [1] |  | 
      
        | Estimated Fair Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 231,727us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 |  |  | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 |  |  | 
      
        | Derivative Liabilities: |  |  |  | 
      
        | Interest rate swaps, treated as hedges | 1,287us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | [1] |  | 
      
        | Interest rate swapsand TBAs, not treated as hedges | 3,352us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 | [1] |  | 
      
        | Non-Agency RMBS [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 44,460us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_ResidentialMortgageBackedSecuritiesMember
 | [2] |  | 
      
        | CDO Securities [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 8,538us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CollateralizedDebtObligationsMember
 | [2],[3],[4] |  | 
      
        | FNMA/FHLMC Securities [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 409,037us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_USGovernmentAgenciesDebtSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Level 2 [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel2Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Derivative Liabilities: |  |  |  | 
      
        | Interest rate swaps, treated as hedges | 1,287us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel2Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Interest rate swapsand TBAs, not treated as hedges | 3,352us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsLiabilitiesAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel2Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Derivative liabilities | 4,639us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel2Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Level 3 Inputs [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 223,189us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel3Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Level 3 Internal Pricing [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 8,538us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = nct_FairValueInputsLevel3InternalPricingMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Carrying Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 231,727us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Derivative Liabilities: |  |  |  | 
      
        | Interest rate swaps, treated as hedges | 1,287us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Interest rate swapsand TBAs, not treated as hedges | 3,352us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Derivative liabilities | 4,639us-gaap_DerivativeLiabilities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Estimated Fair Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 231,727us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Derivative Liabilities: |  |  |  | 
      
        | Interest rate swaps, treated as hedges | 1,287us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Interest rate swapsand TBAs, not treated as hedges | 3,352us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsLiabilitiesAtFairValue / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Derivative liabilities | 4,639us-gaap_DerivativeLiabilities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | CMBS [Member] | Level 3 Inputs [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 178,729us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel3Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CommercialMortgageBackedSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | CMBS [Member] | Carrying Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 178,729us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CommercialMortgageBackedSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | CMBS [Member] | Estimated Fair Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 178,729us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CommercialMortgageBackedSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Non-Agency RMBS [Member] | Level 3 Inputs [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 44,460us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel3Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_ResidentialMortgageBackedSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Non-Agency RMBS [Member] | Carrying Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 44,460us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_ResidentialMortgageBackedSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | Non-Agency RMBS [Member] | Estimated Fair Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 44,460us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_ResidentialMortgageBackedSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | CDO Securities [Member] | Level 3 Internal Pricing [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 8,538us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = nct_FairValueInputsLevel3InternalPricingMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CollateralizedDebtObligationsMember
 | [5],[6] |  | 
      
        | Measured on a Recurring Basis [Member] | CDO Securities [Member] | Carrying Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 8,538us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CollateralizedDebtObligationsMember
 | [5],[6] |  | 
      
        | Measured on a Recurring Basis [Member] | CDO Securities [Member] | Estimated Fair Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, available-for-sale | 8,538us-gaap_AvailableForSaleSecuritiesDebtSecurities / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_CollateralizedDebtObligationsMember
 | [5],[6] |  | 
      
        | Measured on a Recurring Basis [Member] | FNMA/FHLMC Securities [Member] | Level 2 [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, pledged as collateral | 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByFairValueHierarchyLevelAxis
 = us-gaap_FairValueInputsLevel2Member
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_USGovernmentAgenciesDebtSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | FNMA/FHLMC Securities [Member] | Carrying Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, pledged as collateral | 490,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_CarryingReportedAmountFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_USGovernmentAgenciesDebtSecuritiesMember
 |  |  | 
      
        | Measured on a Recurring Basis [Member] | FNMA/FHLMC Securities [Member] | Estimated Fair Value [Member] |  |  |  | 
      
        | Assets: |  |  |  | 
      
        | Real estate securities, pledged as collateral | $ 409,037us-gaap_PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment / us-gaap_FairValueByMeasurementBasisAxis
 = us-gaap_EstimateOfFairValueFairValueDisclosureMember
 / us-gaap_FairValueByMeasurementFrequencyAxis
 = us-gaap_FairValueMeasurementsRecurringMember
 / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
 = us-gaap_USGovernmentAgenciesDebtSecuritiesMember
 |  |  | 
      
        |  | 
      
        |  |