v2.4.1.9

Fair Value Measurements (Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013
--- | --- | ---
Cash and cash equivalents | $ 1,546 us-gaap_CashAndCashEquivalentsFairValueDisclosure | $ 974 us-gaap_CashAndCashEquivalentsFairValueDisclosure
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 377 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure | 225 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure
Corporate securities | 556 cnc_CorporateSecuritiesFairValueDisclosure | 296 cnc_CorporateSecuritiesFairValueDisclosure
Municipal securities, General obligation | 54 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure | 54 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure
Municipal securities, Pre-refunded | 5 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure | 11 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure
Municipal securities, Revenue | 102 cnc_RevenueMunicipalSecuritiesFairValueDisclosure | 69 cnc_RevenueMunicipalSecuritiesFairValueDisclosure
Municipal securities, Variable rate demand notes | 14 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure | 29 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure
Asset backed securities | 180 cnc_AssetBackedSecuritiesFairValueDisclosure | 139 cnc_AssetBackedSecuritiesFairValueDisclosure
Mortgage backed securities | 85 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure | 34 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure
Total investments | 1,373 us-gaap_InvestmentsFairValueDisclosure | 857 us-gaap_InvestmentsFairValueDisclosure
Cash and cash equivalents | 79 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure | 27 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure
Certificates of deposit | 6 cnc_CertificatesOfDepositRestrictedFairValueDisclosure | 6 cnc_CertificatesOfDepositRestrictedFairValueDisclosure
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 15 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure | 14 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure
Total restricted deposits | 100 cnc_TotalRestrictedDepositsFairValueDisclosure | 47 cnc_TotalRestrictedDepositsFairValueDisclosure
Interest rate swap agreements | 11 us-gaap_InterestRateDerivativeAssetsAtFairValue | 10 us-gaap_InterestRateDerivativeAssetsAtFairValue
Total assets at fair value | 3,030 us-gaap_AssetsFairValueDisclosure | 1,888 us-gaap_AssetsFairValueDisclosure
Level I [Member] |  |
Cash and cash equivalents | 1,546 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 974 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 360 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 213 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Corporate securities | 0 cnc_CorporateSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 cnc_CorporateSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Municipal securities, General obligation | 0 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Municipal securities, Pre-refunded | 0 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Municipal securities, Revenue | 0 cnc_RevenueMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 cnc_RevenueMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Municipal securities, Variable rate demand notes | 0 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Asset backed securities | 0 cnc_AssetBackedSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 cnc_AssetBackedSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Mortgage backed securities | 0 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Total investments | 360 us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 213 us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Cash and cash equivalents | 79 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 27 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Certificates of deposit | 6 cnc_CertificatesOfDepositRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 6 cnc_CertificatesOfDepositRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 15 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 14 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Total restricted deposits | 100 cnc_TotalRestrictedDepositsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 47 cnc_TotalRestrictedDepositsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Interest rate swap agreements | 0 us-gaap_InterestRateDerivativeAssetsAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 0 us-gaap_InterestRateDerivativeAssetsAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Total assets at fair value | 2,006 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member | 1,234 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Level II [Member] |  |
Cash and cash equivalents | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 17 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 12 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Corporate securities | 556 cnc_CorporateSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 296 cnc_CorporateSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Municipal securities, General obligation | 54 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 54 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Municipal securities, Pre-refunded | 5 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 11 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Municipal securities, Revenue | 102 cnc_RevenueMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 69 cnc_RevenueMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Municipal securities, Variable rate demand notes | 14 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 29 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Asset backed securities | 180 cnc_AssetBackedSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 139 cnc_AssetBackedSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Mortgage backed securities | 85 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 34 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Total investments | 1,013 us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 644 us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Cash and cash equivalents | 0 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 0 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Certificates of deposit | 0 cnc_CertificatesOfDepositRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 0 cnc_CertificatesOfDepositRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 0 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 0 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Total restricted deposits | 0 cnc_TotalRestrictedDepositsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 0 cnc_TotalRestrictedDepositsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Interest rate swap agreements | 11 us-gaap_InterestRateDerivativeAssetsAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 10 us-gaap_InterestRateDerivativeAssetsAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Total assets at fair value | 1,024 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member | 654 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Level III [Member] |  |
Cash and cash equivalents | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 0 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Corporate securities | 0 cnc_CorporateSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_CorporateSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Municipal securities, General obligation | 0 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Municipal securities, Pre-refunded | 0 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Municipal securities, Revenue | 0 cnc_RevenueMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_RevenueMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Municipal securities, Variable rate demand notes | 0 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Asset backed securities | 0 cnc_AssetBackedSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_AssetBackedSecuritiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Mortgage backed securities | 0 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Total investments | 0 us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Cash and cash equivalents | 0 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Certificates of deposit | 0 cnc_CertificatesOfDepositRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_CertificatesOfDepositRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
U.S. Treasury securities and obligations of U.S. government corporations and agencies | 0 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Total restricted deposits | 0 cnc_TotalRestrictedDepositsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 cnc_TotalRestrictedDepositsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Interest rate swap agreements | 0 us-gaap_InterestRateDerivativeAssetsAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | 0 us-gaap_InterestRateDerivativeAssetsAtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Total assets at fair value | $ 0 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member | $ 0 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member

X
- Definition This element represents asset backed securities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_AssetBackedSecuritiesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents restricted cash and cash equivalents reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_CashAndCashEquivalentsRestrictedFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents restricted certificates of deposit reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_CertificatesOfDepositRestrictedFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Corporate securities + References No definition available. + Details
Name: | cnc_CorporateSecuritiesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents general obligation municipal securities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_GeneralObligationMunicipalSecuritiesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Pre Refunded Municipal Securities Fair Value Disclosure + References No definition available. + Details
Name: | cnc_PreRefundedMunicipalSecuritiesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents revenue municipal securities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_RevenueMunicipalSecuritiesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents total restricted deposits reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_TotalRestrictedDepositsFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents U.S. Treasury securities and obligations of U.S. government corporations and agencies reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents restricted U.S. Treasury securities and obligations of U.S. government corporations and agencies reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_UsTreasurySecuritiesAndObligationsOfUsGovernmentCorporationsAndAgenciesRestrictedFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents variable rate demand note municipal securities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | cnc_VariableRateDemandNotesMunicipalSecuritiesFairValueDisclosure
Namespace Prefix: | cnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph a, f, g -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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- Definition Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Mortgage-Backed Securities -URI http://asc.fasb.org/extlink&oid=6517959 + Details
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