Quarterly report pursuant to Section 13 or 15(d)

Acquisitions - Narrative (Details)

v3.20.1
Acquisitions - Narrative (Details)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended
Jan. 23, 2020
USD ($)
$ / shares
shares
Mar. 31, 2020
USD ($)
Mar. 31, 2019
USD ($)
Business Acquisition [Line Items]      
Centene stock price (in usd per share) | $ / shares $ 66.76    
Acquisition related costs   $ 313  
Gain on divestiture   (93) $ 0
Centene Illinois Medicaid and Medicare Advantage Health Plans      
Business Acquisition [Line Items]      
Gain on divestiture $ (93)    
WellCare Health Plans, Inc.      
Business Acquisition [Line Items]      
Transaction value 19,555    
Consideration transferred 17,605    
Consideration transferred, shares valued 11,431    
Cash paid 6,079    
Consideration transferred related to fair value of replacement equity awards associated with pre-combination service $ 95    
Common stock cancelled and converted into right to Centene common stock 3.38    
Cash paid per acquiree share, without interest (in usd per share) | $ / shares $ 120.00    
Shares issued (in shares) | shares 171    
Pro forma revenue (unaudited)   $ 27,815 $ 25,169