Annual report pursuant to Section 13 and 15(d)


Cover - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2020
Feb. 19, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-31826    
Entity Registrant Name Centene Corporation    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 42-1406317    
Entity Address, Address Line One 7700 Forsyth Boulevard    
Entity Address, City or Town St. Louis,    
Entity Address, State or Province MO    
Entity Address, Postal Zip Code 63105    
City Area Code 314    
Local Phone Number 725-4477    
Title of 12(b) Security Common Stock, $0.001 Par Value    
Trading Symbol CNC    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Public Float     $ 36.8
Entity Common Stock, Shares Outstanding   581,593,037  
Documents Incorporated by Reference Portions of the Proxy Statement for the registrant's 2021 annual meeting of stockholders are incorporated by reference in Part III, Items 10, 11, 12, 13 and 14.    
Entity Central Index Key 0001071739    
ICFR Auditor Attestation Flag true    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Amendment Flag false