v3.8.0.1

Summary of Significant Accounting Policies - Affordable Care Act (Details) | 12 Months Ended
--- | ---
Dec. 31, 2016
Accounting Policies [Abstract] |
Reinsurance reimbursement threshold | $90,000 entitled the Company to reimbursement from the programs at 50%

X
- Definition Reinsurance reimbursement threshold + References No definition available. + Details
Name: | cnc_Reinsurancereimbursementthreshold
Namespace Prefix: | cnc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration