Stockholders' Equity	12 Months Ended
Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders' Equity The Company has 10 million authorized shares of preferred stock at $.001 par value. At December 31, 2018, there were no preferred shares outstanding. The Company's Board of Directors has authorized a stock repurchase program for up to 16 million shares of the Company's common stock from time to time on the open market or through privately negotiated transactions. No duration has been placed on the repurchase program. The Company has 7 million available shares remaining under the program for repurchases as of December 31, 2018. The Company reserves the right to discontinue the repurchase program at any time. During the year ended December 31, 2018, the Company did not repurchase any shares through this publicly announced program. As a component of the employee stock compensation plan, employees can use shares of stock which have vested to satisfy statutory tax withholding obligations. As part of this plan, the Company repurchased 1 million shares at an aggregate cost of $71 million in 2018 and 1 million shares at an aggregate cost of $65 million in 2017. These shares are included in the Company's treasury stock. In May 2018, the Company completed a registered offering of 53 million shares of Centene common stock with a fair value of $2,860 million. This included the 10% over allotment option to purchase additional shares from the Company which was exercised in full by the underwriters. Net proceeds after underwriting discounts and commissions was $2,779 million. The Company used the net proceeds of the offering to finance a portion of the cash consideration in connection with the Fidelis Care acquisition, to pay related fees and expenses, and for general corporate purposes, including the repayment of outstanding indebtedness. In April 2018, the Company acquired MHM Services Inc. (MHM) and issued 3 million shares of Centene common stock to the selling shareholders, with a fair value of $183 million. In March 2018, the Company acquired Community Medical Holdings Corp., d/b/a Community Medical Group (CMG) and issued 3 million shares of Centene common stock to the selling shareholders, with a fair value of $149 million. In March 2018, the Company acquired an additional 61% of Interpreta Holdings, Inc. (Interpreta) and issued 3 million shares of Centene common stock to the selling shareholders, with a fair value of $175 million.

Stockholders' Equity

The Company has 10 million authorized shares of preferred stock at $.001 par value. At December 31, 2018, there were no preferred shares outstanding.

The Company's Board of Directors has authorized a stock repurchase program for up to 16 million shares of the Company's common stock from time to time on the open market or through privately negotiated transactions. No duration has been placed on the repurchase program. The Company has 7 million available shares remaining under the program for repurchases as of December 31, 2018. The Company reserves the right to discontinue the repurchase program at any time. During the year ended December 31, 2018, the Company did not repurchase any shares through this publicly announced program.

As a component of the employee stock compensation plan, employees can use shares of stock which have vested to satisfy statutory tax withholding obligations. As part of this plan, the Company repurchased 1 million shares at an aggregate cost of $71 million in 2018 and 1 million shares at an aggregate cost of $65 million in 2017. These shares are included in the Company's treasury stock.

In May 2018, the Company completed a registered offering of 53 million shares of Centene common stock with a fair value of $2,860 million. This included the 10% over allotment option to purchase additional shares from the Company which was exercised in full by the underwriters. Net proceeds after underwriting discounts and commissions was $2,779 million. The Company used the net proceeds of the offering to finance a portion of the cash consideration in connection with the Fidelis Care acquisition, to pay related fees and expenses, and for general corporate purposes, including the repayment of outstanding indebtedness.

In April 2018, the Company acquired MHM Services Inc. (MHM) and issued 3 million shares of Centene common stock to the selling shareholders, with a fair value of $183 million.

In March 2018, the Company acquired Community Medical Holdings Corp., d/b/a Community Medical Group (CMG) and issued 3 million shares of Centene common stock to the selling shareholders, with a fair value of $149 million.

In March 2018, the Company acquired an additional 61% of Interpreta Holdings, Inc. (Interpreta) and issued 3 million shares of Centene common stock to the selling shareholders, with a fair value of $175 million.