v2.4.1.9
Summary Of Significant Accounting Policies (Health Insurer Fee) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Dec. 31, 2014
Health Insurer Fee [Abstract]  
Risk Adjustment Payable $ 44cnc_RiskAdjustmentPayable
Minimum medical loss ratio payable 6cnc_Minimummedicallossratiopayable
Reinsurance reimbursement threshold ($45,000 with 80% coinsurance)
Reinsurance Receivables 11us-gaap_ReinsuranceReceivablesPaidLossesRecoverable
Risk Corridor Payable $ 9cnc_RiskCorridorPayable