Basis of Presentation and Significant Events	6 Months Ended
Jun. 30, 2015
Basis of Presentation [Abstract]
Basis of Accounting and Significant Events [Text Block]	BASIS OF PRESENTATION AND SIGNIFICANT EVENTS Basis of Presentation Health Net, Inc. prepared the accompanying unaudited consolidated financial statements following the rules and regulations of the U.S. Securities and Exchange Commission ("SEC") for interim reporting. In this Quarterly Report on Form 10-Q, unless the context otherwise requires, the terms “Company,” “Health Net,” “we,” “us,” and “our” refer to Health Net, Inc. and its subsidiaries. As permitted under those rules and regulations, certain notes or other financial information that are normally required by accounting principles generally accepted in the United States of America ("GAAP") have been condensed or omitted if they substantially duplicate the disclosures contained in the annual audited financial statements. The accompanying unaudited consolidated financial statements should be read together with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2014 ("Form 10-K"). We are responsible for the accompanying unaudited consolidated financial statements. These consolidated financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of our financial position and operating results in accordance with GAAP. In accordance with GAAP, we make certain estimates and assumptions that affect the reported amounts. Actual results could differ from those estimates and assumptions. In addition, revenues, expenses, assets and liabilities can vary during each quarter of the year. Therefore, the results and trends in these interim financial statements may not be indicative of those for the full year. Significant Events Proposed Merger On July 2, 2015, the Company entered into an Agreement and Plan of Merger (the "Merger Agreement") with Centene Corporation, a Delaware corporation ("Centene"), together with Chopin Merger Sub I, Inc. ("Merger Sub I") and Chopin Merger Sub II, Inc. ("Merger Sub II"), each a Delaware corporation and a direct, wholly-owned subsidiary of Centene. Upon the terms and subject to the conditions set forth in the Merger Agreement, (i) Merger Sub I will merge with and into the Company (the "Merger"), with the Company as the surviving corporation (the "Surviving Corporation") and (ii) subject to delivery of a legal opinion from counsel to the Surviving Corporation regarding certain aspects of the tax treatment of the transactions, immediately after the consummation of the Merger, the Surviving Corporation will merge with and into Merger Sub II, with Merger Sub II continuing as the surviving company. At the effective time of the Merger, the Company's existing stockholders will receive per share merger consideration consisting of $28.25 in cash and 0.6220 of one share of Centene's common stock. The Company and Centene each have agreed, subject to certain exceptions, not to directly or indirectly solicit competing acquisition proposals or to enter into, continue or participate in discussions or negotiations concerning, or enter into any letter of intent, memorandum of understanding, merger agreement or other agreement relating to, an alternative business combination. However, the board of directors of the Company may, subject to certain conditions, withdraw its recommendation that its stockholders vote in favor of adoption of the Merger Agreement and terminate the Merger Agreement, and the Centene board of directors may, subject to certain conditions, withdraw its recommendation that its stockholders vote in favor of approval of the issuance of common stock forming part of the Merger Consideration and terminate the Merger Agreement, in connection with the receipt of an alternative proposal that the Company's board or Centene's board, as the case may be, determines constitutes a superior proposal, and such board determines in good faith that a failure to effect such a withdrawal of recommendation would be inconsistent with its fiduciary duties. The completion of the Merger is subject to the satisfaction or waiver of customary closing conditions, including approval by the Company's stockholders of the adoption of the Merger Agreement and approval by Centene's stockholders of the issuance of the common stock forming part of the merger consideration, as well as various regulatory approvals. The completion of the Merger is not conditioned on receipt of financing by Centene. The Merger is expected to close by early 2016. Cognizant Transaction On November 2, 2014, we entered into a master services agreement (as subsequently amended and restated, the "Master Services Agreement") with Cognizant Healthcare Services, LLC to provide certain services to us. In connection with the Master Services Agreement, we also entered into an asset purchase agreement (the "Asset Purchase Agreement") pursuant to which we have agreed to sell certain software assets and related intellectual property we own to Cognizant (the "Asset Sale," and together with the transactions contemplated by the Master Services Agreement, the "Cognizant Transaction"). The closing of the Cognizant Transaction and commencement of services under the Master Services Agreement on the BPaaS Services Commencement Date (as defined in the Master Services Agreement), is subject to receipt of required regulatory approvals, and the closing of the related Asset Sale is scheduled for the BPaaS Services Commencement Date. As of June 30, 2015 and December 31, 2014, respectively, we have classified $50.0 million, at fair value less cost to sell, in assets as assets held for sale. See Note 3 for additional information about our agreement with Cognizant and the assets held for sale, and Note 11 for additional information regarding our subsequent amendment to the Master Services Agreement.

BASIS OF PRESENTATION AND SIGNIFICANT EVENTS

Basis of Presentation

Health Net, Inc. prepared the accompanying unaudited consolidated financial statements following the rules and regulations of the U.S. Securities and Exchange Commission ("SEC") for interim reporting. In this Quarterly Report on Form 10-Q, unless the context otherwise requires, the terms “Company,” “Health Net,” “we,” “us,” and “our” refer to Health Net, Inc. and its subsidiaries. As permitted under those rules and regulations, certain notes or other financial information that are normally required by accounting principles generally accepted in the United States of America ("GAAP") have been condensed or omitted if they substantially duplicate the disclosures contained in the annual audited financial statements. The accompanying unaudited consolidated financial statements should be read together with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2014 ("Form 10-K").

We are responsible for the accompanying unaudited consolidated financial statements. These consolidated financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of our financial position and operating results in accordance with GAAP. In accordance with GAAP, we make certain estimates and assumptions that affect the reported amounts. Actual results could differ from those estimates and assumptions. In addition, revenues, expenses, assets and liabilities can vary during each quarter of the year. Therefore, the results and trends in these interim financial statements may not be indicative of those for the full year.

Significant Events

Proposed Merger

On July 2, 2015, the Company entered into an Agreement and Plan of Merger (the "Merger Agreement") with Centene Corporation, a Delaware corporation ("Centene"), together with Chopin Merger Sub I, Inc. ("Merger Sub I") and Chopin Merger Sub II, Inc. ("Merger Sub II"), each a Delaware corporation and a direct, wholly-owned subsidiary of Centene. Upon the terms and subject to the conditions set forth in the Merger Agreement, (i) Merger Sub I will merge with and into the Company (the "Merger"), with the Company as the surviving corporation (the "Surviving Corporation") and (ii) subject to delivery of a legal opinion from counsel to the Surviving Corporation regarding certain aspects of the tax treatment of the transactions, immediately after the consummation of the Merger, the Surviving Corporation will merge with and into Merger Sub II, with Merger Sub II continuing as the surviving company.

At the effective time of the Merger, the Company's existing stockholders will receive per share merger consideration consisting of $28.25 in cash and 0.6220 of one share of Centene's common stock.

The Company and Centene each have agreed, subject to certain exceptions, not to directly or indirectly solicit competing acquisition proposals or to enter into, continue or participate in discussions or negotiations concerning, or enter into any letter of intent, memorandum of understanding, merger agreement or other agreement relating to, an alternative business combination. However, the board of directors of the Company may, subject to certain conditions, withdraw its recommendation that its stockholders vote in favor of adoption of the Merger Agreement and terminate the Merger Agreement, and the Centene board of directors may, subject to certain conditions, withdraw its recommendation that its stockholders vote in favor of approval of the issuance of common stock forming part of the Merger Consideration and terminate the Merger Agreement, in connection with the receipt of an alternative proposal that the Company's board or Centene's board, as the case may be, determines constitutes a superior proposal, and such board determines in good faith that a failure to effect such a withdrawal of recommendation would be inconsistent with its fiduciary duties.

The completion of the Merger is subject to the satisfaction or waiver of customary closing conditions, including approval by the Company's stockholders of the adoption of the Merger Agreement and approval by Centene's stockholders of the issuance of the common stock forming part of the merger consideration, as well as various regulatory approvals. The completion of the Merger is not conditioned on receipt of financing by Centene. The Merger is expected to close by early 2016.

Cognizant Transaction

On November 2, 2014, we entered into a master services agreement (as subsequently amended and restated, the "Master Services Agreement") with Cognizant Healthcare Services, LLC to provide certain services to us. In connection with the Master Services Agreement, we also entered into an asset purchase agreement (the "Asset Purchase Agreement") pursuant to which we have agreed to sell certain software assets and related intellectual property we own to Cognizant (the "Asset Sale," and together with the transactions contemplated by the Master Services Agreement, the "Cognizant Transaction"). The closing of the Cognizant Transaction and commencement of services under the Master Services Agreement on the BPaaS Services Commencement Date (as defined in the Master Services Agreement), is subject to receipt of required regulatory approvals, and the closing of the related Asset Sale is scheduled for the BPaaS Services Commencement Date.

As of June 30, 2015 and December 31, 2014, respectively, we have classified $50.0 million, at fair value less cost to sell, in assets as assets held for sale. See Note 3 for additional information about our agreement with Cognizant and the assets held for sale, and Note 11 for additional information regarding our subsequent amendment to the Master Services Agreement.