v2.4.1.9

Goodwill And Intangible Assets (Schedule Of Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items] |  |  |
Amortization expenses | $ 16 us-gaap_AmortizationOfIntangibleAssets | $ 6 us-gaap_AmortizationOfIntangibleAssets | $ 5 us-gaap_AmortizationOfIntangibleAssets
Intangible assets | 163 us-gaap_FiniteLivedIntangibleAssetsGross | 80 us-gaap_FiniteLivedIntangibleAssetsGross |
Weighted Average Life in Years | 10 years 3 months | 11 years 1 month 6 days |
Total accumulated amortization | (43)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization | (31)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization |
Intangible Assets, Net, Total | 120 us-gaap_FiniteLivedIntangibleAssetsNet | 49 us-gaap_FiniteLivedIntangibleAssetsNet |
Purchased Contract Rights [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Intangible assets | 28 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember | 22 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember |
Weighted Average Life in Years | 7 years 6 months | 7 years 6 months |
Total accumulated amortization | (14)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember | (14)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_ContractualRightsMember |
Provider Contracts [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Intangible assets | 103 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = cnc_ProviderContractsMember | 36 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = cnc_ProviderContractsMember |
Weighted Average Life in Years | 11 years 1 month | 13 years 2 months 18 days |
Total accumulated amortization | (14)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = cnc_ProviderContractsMember | (4)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = cnc_ProviderContractsMember |
Customer Relationships [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Intangible assets | 15 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember | 13 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember |
Weighted Average Life in Years | 7 years 1 month | 8 years |
Total accumulated amortization | (12)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember | (11)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember |
Trade Names [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Intangible assets | 17 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember | 9 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember |
Weighted Average Life in Years | 13 years 1 month | 18 years 10 months 18 days |
Total accumulated amortization | $ (3)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember | $ (2)us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_TradeNamesMember |

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References 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 350 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 + Details
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- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 + Details
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- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 + Details
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- Definition Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 + Details
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- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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