BASIS OF PRESENTATION AND SIGNIFICANT EVENTS	9 Months Ended
Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION AND SIGNIFICANT EVENTS	BASIS OF PRESENTATION AND SIGNIFICANT EVENTS The accompanying condensed consolidated financial statements are presented in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the disclosures normally required by accounting principles generally accepted in the United States of America, or GAAP, or those normally made in an Annual Report on Form 10-K. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. For further information, the reader of this Form 10-Q should refer to our Form 10-K for the year ended December 31, 2017, that was filed with the Securities and Exchange Commission, or the SEC, on February 16, 2018. We refer to the Form 10-K as the “2017 Form 10-K” in this document. References throughout this document to “we,” “us,” “our,” “Company,” and “Humana” mean Humana Inc. and its subsidiaries. The preparation of our condensed consolidated financial statements in accordance with GAAP requires us to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. The areas involving the most significant use of estimates are the estimation of benefits payable, future policy benefits payable, the impact of risk adjustment provisions related to our Medicare contracts, the valuation and related impairment recognition of investment securities, and the valuation and related impairment recognition of long-lived assets, including goodwill. These estimates are based on knowledge of current events and anticipated future events, and accordingly, actual results may ultimately differ materially from those estimates. Refer to Note 2 to the consolidated financial statements included in our 2017 Form 10-K for information on accounting policies that we consider in preparing our consolidated financial statements. The financial information has been prepared in accordance with our customary accounting practices and has not been audited. In our opinion, the information presented reflects all adjustments necessary for a fair statement of interim results. All such adjustments are of a normal and recurring nature. Workforce Optimization During the third quarter of 2017, we initiated a voluntary early retirement program and an involuntary workforce reduction program. These programs impacted approximately 3,600 associates, or 7.8%, of our workforce in 2017. As a result, in 2017 we recorded charges of $148 million, or $0.64 per diluted common share. At December 31, 2017, $140 million was classified as a current liability, included in our condensed consolidated balance sheet in the trade accounts payable and accrued expenses line. Payments under these programs are being made upon termination during the early retirement or severance pay period. The remaining workforce optimization liability at September 30, 2018 was $29 million and is expected to be substantially paid in 2018. Aetna Merger On February 16, 2017, under the terms of the Agreement and Plan of Merger, or Merger Agreement, with Aetna Inc., and certain wholly owned subsidiaries of Aetna Inc., which we collectively refer to as Aetna, we received a breakup fee of $1 billion from Aetna, which is included in our consolidated statement of income in the line captioned "Merger termination fee and related costs, net." Revenue Recognition Our revenues include premium and service revenues. Service revenues include administrative service fees that are recorded based upon established per member per month rates and the number of members for the month and are recognized as services are provided for the month. Additionally, service revenues include net patient service revenues that are recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For more information about our revenues, refer to Note 2 to the consolidated financial statements included in our 2017 Form 10-K for information on accounting policies that we consider in preparing our consolidated financial statements. See Note 15 for disaggregation of revenue by segment and type. At September 30, 2018, accounts receivable related to services were $148 million. For the three and nine months ended September 30, 2018, we had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the condensed consolidated balance sheet at September 30, 2018. For the three and nine months ended September 30, 2018, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price), was not material. Further, revenue expected to be recognized in any future year related to remaining performance obligations was not material.

BASIS OF PRESENTATION AND SIGNIFICANT EVENTS

The accompanying condensed consolidated financial statements are presented in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the disclosures normally required by accounting principles generally accepted in the United States of America, or GAAP, or those normally made in an Annual Report on Form 10-K. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. For further information, the reader of this Form 10-Q should refer to our Form 10-K for the year ended December 31, 2017, that was filed with the Securities and Exchange Commission, or the SEC, on February 16, 2018. We refer to the Form 10-K as the “2017 Form 10-K” in this document. References throughout this document to “we,” “us,” “our,” “Company,” and “Humana” mean Humana Inc. and its subsidiaries.

The preparation of our condensed consolidated financial statements in accordance with GAAP requires us to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. The areas involving the most significant use of estimates are the estimation of benefits payable, future policy benefits payable, the impact of risk adjustment provisions related to our Medicare contracts, the valuation and related impairment recognition of investment securities, and the valuation and related impairment recognition of long-lived assets, including goodwill. These estimates are based on knowledge of current events and anticipated future events, and accordingly, actual results may ultimately differ materially from those estimates. Refer to Note 2 to the consolidated financial statements included in our 2017 Form 10-K for information on accounting policies that we consider in preparing our consolidated financial statements.

The financial information has been prepared in accordance with our customary accounting practices and has not been audited. In our opinion, the information presented reflects all adjustments necessary for a fair statement of interim results. All such adjustments are of a normal and recurring nature.

Workforce Optimization

During the third quarter of 2017, we initiated a voluntary early retirement program and an involuntary workforce reduction program. These programs impacted approximately 3,600 associates, or 7.8%, of our workforce in 2017. As a result, in 2017 we recorded charges of $148 million, or $0.64 per diluted common share. At December 31, 2017, $140 million was classified as a current liability, included in our condensed consolidated balance sheet in the trade accounts payable and accrued expenses line. Payments under these programs are being made upon termination during the early retirement or severance pay period. The remaining workforce optimization liability at September 30, 2018 was $29 million and is expected to be substantially paid in 2018.

Aetna Merger

On February 16, 2017, under the terms of the Agreement and Plan of Merger, or Merger Agreement, with Aetna Inc., and certain wholly owned subsidiaries of Aetna Inc., which we collectively refer to as Aetna, we received a breakup fee of $1 billion from Aetna, which is included in our consolidated statement of income in the line captioned "Merger termination fee and related costs, net."

Revenue Recognition

Our revenues include premium and service revenues. Service revenues include administrative service fees that are recorded based upon established per member per month rates and the number of members for the month and are recognized as services are provided for the month. Additionally, service revenues include net patient service revenues that are recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For more information about our revenues, refer to Note 2 to the consolidated financial statements included in our 2017 Form 10-K for information on accounting policies that we consider in preparing our consolidated financial statements. See Note 15 for disaggregation of revenue by segment and type.

At September 30, 2018, accounts receivable related to services were $148 million. For the three and nine months ended September 30, 2018, we had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the condensed consolidated balance sheet at September 30, 2018.

For the three and nine months ended September 30, 2018, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price), was not material. Further, revenue expected to be recognized in any future year related to remaining performance obligations was not material.