v3.8.0.1

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | ---
Mar. 24, 2016 | Jan. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Class of Stock [Line Items] |  |  |  |  |
Preferred stock, shares authorized (in shares) |  |  | 10,000,000 | 10,000,000 |
Preferred stock, par value (in usd per share) |  |  | $ 0.001 | $ 0.001 |
Preferred stock, shares outstanding (in shares) |  |  | 0 | 0 |
Common stock, shares authorized to repurchase |  |  | 8,000,000 |  |
Remaining number of shares available to be repurchased |  |  | 3,335,000 |  |
Treasury stock, shares, acquired |  |  | 727,000 | 1,078,000 |
Payments for repurchase of common stock (in usd) |  |  | $ 65 | $ 63 | $ 53
Percentage of voting interests acquired |  | 19.00% |  |  |
Stock issued during period, shares, new issues |  | 1,144,000 |  |  |
Health Net, Inc. |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |
Common stock issued for acquisitions (in shares) | 48,449,000 |  |  |  |
Business acquisition, consideration transferred, Centene common stock issued, value | $ 3,038 |  |  |  |

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