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Income Taxes (Tax Effects Of Temporary Differences Which Give Rise To Deferred Tax Assets And Liabilities) (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2014
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Dec. 31, 2013
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| Income Tax Disclosure [Abstract] | ||
| Medical claims liability | $ 27us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities | $ 20us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities |
| Accrued expenses | 11us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals | 5us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals |
| Net operating loss carryforward | 21us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal | 16us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal |
| Compensation accruals | 53us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost | 31us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost |
| Premium and related receivables | 35cnc_Premiumandrelatedreceivables | 20cnc_Premiumandrelatedreceivables |
| Other | 9us-gaap_DeferredTaxAssetsOther | 16us-gaap_DeferredTaxAssetsOther |
| Deferred tax assets | 156us-gaap_DeferredTaxAssetsGross | 108us-gaap_DeferredTaxAssetsGross |
| Valuation allowance | (12)us-gaap_DeferredTaxAssetsValuationAllowance | (8)us-gaap_DeferredTaxAssetsValuationAllowance |
| Net deferred tax assests | 144us-gaap_DeferredTaxAssetsNet | 100us-gaap_DeferredTaxAssetsNet |
| Intangible assets | 25us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets | 18us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets |
| Prepaid assets | 6cnc_DeferredTaxLiabilitiesPrepaidAssetsAndOtherCurrent | 6cnc_DeferredTaxLiabilitiesPrepaidAssetsAndOtherCurrent |
| Depreciation and amortization | 26cnc_DeferredTaxLiabilitiesDepreciationAndAmortizationNoncurrent | 30cnc_DeferredTaxLiabilitiesDepreciationAndAmortizationNoncurrent |
| Other | 4us-gaap_DeferredTaxLiabilitiesOther | 2us-gaap_DeferredTaxLiabilitiesOther |
| Deferred Tax Liabilities | 61us-gaap_DeferredIncomeTaxLiabilities | 56us-gaap_DeferredIncomeTaxLiabilities |
| Net deferred tax assets | $ 83us-gaap_DeferredTaxAssetsLiabilitiesNet | $ 44us-gaap_DeferredTaxAssetsLiabilitiesNet |
| X | ||||||||||
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- Definition
Deferred tax liabilities, Depreciation and amortization, Noncurrent No definition available.
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- Definition
Deferred tax liabilities, Prepaid assets and other, current No definition available.
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- Definition
Premium and related receivables No definition available.
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from accrued liabilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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