BASIS OF PRESENTATION AND SIGNIFICANT EVENTS	3 Months Ended
Mar. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION AND SIGNIFICANT EVENTS	BASIS OF PRESENTATION AND SIGNIFICANT EVENTS Basis of Presentation The condensed consolidated financial statements of Coventry Health Care, Inc. and its subsidiaries (“Coventry” or the “Company”) contained in this report are unaudited but reflect all normal recurring adjustments which, in the opinion of management, are necessary for the fair presentation of the results of the interim periods reflected. Certain information and footnote disclosures normally included in the consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been omitted pursuant to applicable rules and regulations of the Securities and Exchange Commission (“SEC”). The Company has eliminated all significant intercompany balances and transactions. Therefore, it is suggested that these condensed consolidated financial statements be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10–K for the year ended December 31, 2012. The results of operations for the interim periods reported herein are not necessarily indicative of results to be expected for the full year. The year-end balance sheet data included in this report was derived from audited financial statements. Significant Events Proposed Merger On August 19, 2012, the Company, Aetna Inc. (“Aetna”) and Jaguar Merger Subsidiary, Inc. (“Merger Sub”) entered into an Agreement and Plan of Merger, pursuant to which, subject to the satisfaction or waiver of certain conditions, Merger Sub will be merged with and into the Company (the “Merger”), with the Company surviving the Merger as a wholly-owned subsidiary of Aetna. A copy of the Agreement and Plan of Merger was filed as Exhibit 2.1 to the Company’s Current Report on Form 8-K filed on August 20, 2012. The Company subsequently entered into Amendment No. 1 and Amendment No. 2 to the Agreement and Plan of Merger, which were filed as Exhibit 2.1 to the Company’s Current Reports on Form 8-K filed on October 23, 2012 and November 13, 2012, respectively. As used herein, the “Merger Agreement” means the Agreement and Plan of Merger, by and among Coventry, Aetna and Merger Sub, as amended. Under the terms of the Merger Agreement, the Company’s stockholders will receive $27.30 in cash, without interest, and 0.3885 of an Aetna common share for each share of the Company’s common stock. The total transaction was initially estimated at approximately $7.3 billion, including the assumption of Coventry debt, based on the closing price of Aetna common shares on August 17, 2012. On November 21, 2012, the Company’s stockholders voted at the stockholder special meeting to approve the adoption of the Merger Agreement. Of the 104,941,398 shares voting at the special meeting of stockholders, more than 99% voted in favor of the adoption of the Merger Agreement, which represented approximately 78% of the Company’s total outstanding shares of common stock as of the October 15, 2012 record date. The consummation of the Merger is subject to customary closing conditions, including, among others, the adoption of the Merger Agreement by the Company’s stockholders, the absence of certain legal impediments to the consummation of the Merger, the receipt of specified governmental consents and approvals, the early termination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvement Act of 1976, and, subject to certain exceptions, the accuracy of representations and warranties made by the Company and Aetna, respectively, and compliance by the Company and Aetna with their respective obligations under the Merger Agreement. The Merger is expected to close in mid-2013. Revenue Recognition As described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012, the Centers for Medicare and Medicaid Services (“CMS”) periodically performs audits and may seek return of premium payments made to the Company if risk adjustment factors are not properly supported by medical record data. The Company estimates and records reserves for CMS audits based on information available at the time the estimates are made. The judgments and uncertainties affecting the application of these policies include, among other things, significant estimates related to the amount of hierarchical condition category (“HCC”) revenue subject to audit, anticipated error rates, sample methodologies, confidence intervals, enrollee selection, and payment error extrapolation methodology. During the quarter ended March 31, 2012, CMS released a “Notice of Final Payment Error Calculation Methodology for Part C Medicare Advantage Risk Adjustment Data Validation (“RADV”) Contract-Level Audits.” Most importantly, CMS made significant changes regarding which contract years are subject to the CMS RADV audits and other core areas of the audit methodology. As a result of this notice, the Company released RADV reserves, for contract years 2007 through 2011, resulting in an increase in operating earnings of $133.0 million during the quarter ended March 31, 2012.

BASIS OF PRESENTATION AND SIGNIFICANT EVENTS

Basis of Presentation

The condensed consolidated financial statements of Coventry Health Care, Inc. and its subsidiaries (“Coventry” or the “Company”) contained in this report are unaudited but reflect all normal recurring adjustments which, in the opinion of management, are necessary for the fair presentation of the results of the interim periods reflected. Certain information and footnote disclosures normally included in the consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been omitted pursuant to applicable rules and regulations of the Securities and Exchange Commission (“SEC”). The Company has eliminated all significant intercompany balances and transactions. Therefore, it is suggested that these condensed consolidated financial statements be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10–K for the year ended December 31, 2012. The results of operations for the interim periods reported herein are not necessarily indicative of results to be expected for the full year. The year-end balance sheet data included in this report was derived from audited financial statements.

Significant Events

Proposed Merger

On August 19, 2012, the Company, Aetna Inc. (“Aetna”) and Jaguar Merger Subsidiary, Inc. (“Merger Sub”) entered into an Agreement and Plan of Merger, pursuant to which, subject to the satisfaction or waiver of certain conditions, Merger Sub will be merged with and into the Company (the “Merger”), with the Company surviving the Merger as a wholly-owned subsidiary of Aetna. A copy of the Agreement and Plan of Merger was filed as Exhibit 2.1 to the Company’s Current Report on Form 8-K filed on August 20, 2012. The Company subsequently entered into Amendment No. 1 and Amendment No. 2 to the Agreement and Plan of Merger, which were filed as Exhibit 2.1 to the Company’s Current Reports on Form 8-K filed on October 23, 2012 and November 13, 2012, respectively. As used herein, the “Merger Agreement” means the Agreement and Plan of Merger, by and among Coventry, Aetna and Merger Sub, as amended. Under the terms of the Merger Agreement, the Company’s stockholders will receive $27.30 in cash, without interest, and 0.3885 of an Aetna common share for each share of the Company’s common stock. The total transaction was initially estimated at approximately $7.3 billion, including the assumption of Coventry debt, based on the closing price of Aetna common shares on August 17, 2012.

On November 21, 2012, the Company’s stockholders voted at the stockholder special meeting to approve the adoption of the Merger Agreement. Of the 104,941,398 shares voting at the special meeting of stockholders, more than 99% voted in favor of the adoption of the Merger Agreement, which represented approximately 78% of the Company’s total outstanding shares of common stock as of the October 15, 2012 record date.

The consummation of the Merger is subject to customary closing conditions, including, among others, the adoption of the Merger Agreement by the Company’s stockholders, the absence of certain legal impediments to the consummation of the Merger, the receipt of specified governmental consents and approvals, the early termination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvement Act of 1976, and, subject to certain exceptions, the accuracy of representations and warranties made by the Company and Aetna, respectively, and compliance by the Company and Aetna with their respective obligations under the Merger Agreement. The Merger is expected to close in mid-2013.

Revenue Recognition

As described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012, the Centers for Medicare and Medicaid Services (“CMS”) periodically performs audits and may seek return of premium payments made to the Company if risk adjustment factors are not properly supported by medical record data. The Company estimates and records reserves for CMS audits based on information available at the time the estimates are made. The judgments and uncertainties affecting the application of these policies include, among other things, significant estimates related to the amount of hierarchical condition category (“HCC”) revenue subject to audit, anticipated error rates, sample methodologies, confidence intervals, enrollee selection, and payment error extrapolation methodology.

During the quarter ended March 31, 2012, CMS released a “Notice of Final Payment Error Calculation Methodology for Part C Medicare Advantage Risk Adjustment Data Validation (“RADV”) Contract-Level Audits.” Most importantly, CMS made significant changes regarding which contract years are subject to the CMS RADV audits and other core areas of the audit methodology. As a result of this notice, the Company released RADV reserves, for contract years 2007 through 2011, resulting in an increase in operating earnings of $133.0 million during the quarter ended March 31, 2012.