v2.4.1.9

Income Taxes (Reconciliation Of The Tax Provision At The U.S. Federal Statutory Rate To The Provision For Income Taxes) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Income Tax Disclosure [Abstract] |  |  |
Earnings from continuing operations, before income tax expense | $ 457 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments | $ 269 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments | $ 123 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
(Earnings) loss attributable to flow through noncontrolling interest | 4 cnc_LessFlowThroughNoncontrollingInterest | (1)cnc_LessFlowThroughNoncontrollingInterest | 2 cnc_LessFlowThroughNoncontrollingInterest
Earnings from continuing operations, less noncontrolling interest, before income tax expense | 461 cnc_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsLessNoncontrollingInterest | 268 cnc_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsLessNoncontrollingInterest | 125 cnc_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsLessNoncontrollingInterest
Tax provision at the U.S. federal statutory rate | 162 us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate | 94 us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate | 44 us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate
State income taxes, net of federal income tax benefit | 6 us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes | 3 us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes | (2)us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes
Nondeductible compensation | 1 us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost | 12 us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost | 1 us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost
Benefit from reversal of prior years impact of 162(m)(6) regulations | (14)cnc_Benefitfromreversalofprioryearsimpactof162m6regulations | 0 cnc_Benefitfromreversalofprioryearsimpactof162m6regulations | 0 cnc_Benefitfromreversalofprioryearsimpactof162m6regulations
ACA Health Insurer Fee | 44 cnc_ACAHealthInsurerFee | 0 cnc_ACAHealthInsurerFee | 0 cnc_ACAHealthInsurerFee
Nondeductible goodwill impairment | 0 us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses | 0 us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses | 8 us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses
Other, net | (3)us-gaap_IncomeTaxReconciliationOtherReconcilingItems | (2)us-gaap_IncomeTaxReconciliationOtherReconcilingItems | (4)us-gaap_IncomeTaxReconciliationOtherReconcilingItems
Income tax expense | $ 196 us-gaap_IncomeTaxExpenseBenefit | $ 107 us-gaap_IncomeTaxExpenseBenefit | $ 47 us-gaap_IncomeTaxExpenseBenefit

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- Definition Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(1)(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Income Tax Expense (or Benefit) -URI http://asc.fasb.org/extlink&oid=6515339 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319 + Details
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- Definition The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 2 -Article 4 + Details
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible impairment loss. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 + Details
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible equity-based compensation costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 + Details
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority noncontrolling interest income (loss), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, increase (decrease) in enacted tax rate, prior year income taxes, increase (decrease) in deferred tax asset valuation allowance, and other adjustments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 + Details
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