Description of Business and Significant Events	12 Months Ended
Dec. 31, 2015
Description of Business [Abstract]
Description of Business and Significant Events	Description of Business and Significant Events Health Net, Inc. (referred to herein as "Health Net," "the Company," "we," "us," "our" or "HNT") is a publicly traded managed care organization that delivers managed health care services. Together with our subsidiaries, we provide health benefits through our health maintenance organizations ("HMOs"), insured preferred provider organizations ("PPOs"), exclusive provider organization ("EPO"), point of service ("POS") plans and indemnity products, among others, to approximately 6.1 million individuals across the country through group, individual, Medicare (including the Medicare prescription drug benefit commonly referred as "Part D"), Medicaid ("Medi-Cal" in California), and dual eligible programs as well as programs with the the United States Department of Defense ("Department of Defense" or "DoD") and United States Department of Veterans Affairs ("VA"). Our subsidiaries also offer managed health care products related to behavioral health and prescription drugs. Our reportable segments are comprised of Western Region Operations and Government Contracts, each of which is described below. Our health plan services are provided under our Western Region Operations reportable segment, which includes the operations primarily conducted in California, Arizona, Oregon and Washington for our commercial, Medicare and Medicaid health plans, our health and life insurance companies, our pharmaceutical services subsidiary and certain operations of our behavioral health subsidiaries. Our Government Contracts reportable segment includes our government-sponsored managed care federal contract with the DoD under the TRICARE program in the North Region and other health care, mental health and behavioral health government contracts. On April 1, 2011, we began delivering administrative services under the new T-3 contract for the TRICARE North Region ("T-3 contract"). The T-3 contract for the North Region covers Connecticut, Delaware, Illinois, Indiana, Kentucky (except Fort Campbell), Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, Wisconsin and the District of Columbia and portions of Iowa and Missouri. The Company provides administrative services to approximately 2.8 million Military Health System ("MHS") eligible individuals under the T-3 contract. In addition to the beneficiaries that we service under the T-3 contract, we administer contracts with VA to manage the Patient Centered Community Care program ("PC3 Program") and community based outpatient clinics in one state covering approximately 4,083 enrollees, We also provide behavioral health services to military families under the Department of Defense sponsored Military and Family Life Counseling, formerly Military and Family Life Consultant, ("MFLC") program. See Note 2 under the heading "Government Contracts" for additional information on our T-3 contract for the North Region, the MFLC contract and PC3 Program contract. Significant Events Centene Transaction On July 2, 2015, the Company entered into the Merger Agreement with Centene, together with Merger Sub I and Merger Sub II. 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 completion of the Merger is subject to the satisfaction or waiver of customary closing conditions, including, without limitation, certain approval, notice or similar requirements with applicable regulatory authorities. On August 11, 2015, the Antitrust Division of the Department of Justice and the Federal Trade Commission granted early termination of the waiting period under the Hart-Scott Rodino Antitrust Improvements Act of 1976, as amended (the "HSR Act"). On October 23, 2015, our stockholders approved the adoption of the Merger Agreement and Centene’s stockholders approved the issuance of the shares of its common stock forming part of the merger consideration. The completion of the Merger is not conditioned on receipt of financing by Centene. The Merger is expected to close in the first quarter of 2016, subject to the receipt of the remaining required regulatory approvals and satisfaction or waiver of other closing conditions. 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 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), was subject to receipt of required regulatory approvals, and the closing of the related Asset Sale was scheduled for the BPaaS Services Commencement Date. However, in connection with the announcement of the Merger with Centene, we agreed with Cognizant to suspend efforts toward, and defer the occurrence of, the BPaaS Services Commencement Date to provide time for Health Net and Centene to work towards closing the Merger, and accordingly entered into an amendment to the Master Services Agreement on July 1, 2015 (the "Cognizant Amendment"). The decision to suspend efforts toward the BPaaS Services Commencement Date has similarly deferred the Asset Sale. As of December 31, 2014 we had classified $50.0 million, at fair value less cost to sell, in assets as assets held for sale. As a result of the Cognizant Amendment, we reclassified assets held for sale to property and equipment held-for use and resumed depreciation of such assets due to the deferral of the Asset Sale during the three months ended September 30, 2015. As of December 31, 2015, we had no assets held for sale. See Note 3 for additional information about our agreement with Cognizant, the assets previously held for sale and our subsequent amendment to the Master Services Agreement.

Description of Business and Significant Events

Health Net, Inc. (referred to herein as "Health Net," "the Company," "we," "us," "our" or "HNT") is a publicly traded managed care organization that delivers managed health care services. Together with our subsidiaries, we provide health benefits through our health maintenance organizations ("HMOs"), insured preferred provider organizations ("PPOs"), exclusive provider organization ("EPO"), point of service ("POS") plans and indemnity products, among others, to approximately 6.1 million individuals across the country through group, individual, Medicare (including the Medicare prescription drug benefit commonly referred as "Part D"), Medicaid ("Medi-Cal" in California), and dual eligible programs as well as programs with the the United States Department of Defense ("Department of Defense" or "DoD") and United States Department of Veterans Affairs ("VA"). Our subsidiaries also offer managed health care products related to behavioral health and prescription drugs.

Our reportable segments are comprised of Western Region Operations and Government Contracts, each of which is described below.

Our health plan services are provided under our Western Region Operations reportable segment, which includes the operations primarily conducted in California, Arizona, Oregon and Washington for our commercial, Medicare and Medicaid health plans, our health and life insurance companies, our pharmaceutical services subsidiary and certain operations of our behavioral health subsidiaries.

Our Government Contracts reportable segment includes our government-sponsored managed care federal contract with the DoD under the TRICARE program in the North Region and other health care, mental health and behavioral health government contracts. On April 1, 2011, we began delivering administrative services under the new T-3 contract for the TRICARE North Region ("T-3 contract"). The T-3 contract for the North Region covers Connecticut, Delaware, Illinois, Indiana, Kentucky (except Fort Campbell), Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, Wisconsin and the District of Columbia and portions of Iowa and Missouri. The Company provides administrative services to approximately 2.8 million Military Health System ("MHS") eligible individuals under the T-3 contract. In addition to the beneficiaries that we service under the T-3 contract, we administer contracts with VA to manage the Patient Centered Community Care program ("PC3 Program") and community based outpatient clinics in one state covering approximately 4,083 enrollees, We also provide behavioral health services to military families under the Department of Defense sponsored Military and Family Life Counseling, formerly Military and Family Life Consultant, ("MFLC") program. See Note 2 under the heading "Government Contracts" for additional information on our T-3 contract for the North Region, the MFLC contract and PC3 Program contract.

Significant Events

Centene Transaction

On July 2, 2015, the Company entered into the Merger Agreement with Centene, together with Merger Sub I and Merger Sub II. 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 completion of the Merger is subject to the satisfaction or waiver of customary closing conditions, including, without limitation, certain approval, notice or similar requirements with applicable regulatory authorities. On August 11, 2015, the Antitrust Division of the Department of Justice and the Federal Trade Commission granted early termination of the waiting period under the Hart-Scott Rodino Antitrust Improvements Act of 1976, as amended (the "HSR Act"). On October 23, 2015, our stockholders approved the adoption of the Merger Agreement and Centene’s stockholders approved the issuance of the shares of its common stock forming part of the merger consideration.

The completion of the Merger is not conditioned on receipt of financing by Centene. The Merger is expected to close in the first quarter of 2016, subject to the receipt of the remaining required regulatory approvals and satisfaction or waiver of other closing conditions.

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 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), was subject to receipt of required regulatory approvals, and the closing of the related Asset Sale was scheduled for the BPaaS Services Commencement Date. However, in connection with the announcement of the Merger with Centene, we agreed with Cognizant to suspend efforts toward, and defer the occurrence of, the BPaaS Services Commencement Date to provide time for Health Net and Centene to work towards closing the Merger, and accordingly entered into an amendment to the Master Services Agreement on July 1, 2015 (the "Cognizant Amendment"). The decision to suspend efforts toward the BPaaS Services Commencement Date has similarly deferred the Asset Sale.

As of December 31, 2014 we had classified $50.0 million, at fair value less cost to sell, in assets as assets held for sale. As a result of the Cognizant Amendment, we reclassified assets held for sale to property and equipment held-for use and resumed depreciation of such assets due to the deferral of the Asset Sale during the three months ended September 30, 2015. As of December 31, 2015, we had no assets held for sale. See Note 3 for additional information about our agreement with Cognizant, the assets previously held for sale and our subsequent amendment to the Master Services Agreement.