Mergers and Acquisitions	12 Months Ended
Dec. 31, 2016
Acquisitions and Dispositions [Abstract]
Acquisitions and Dispositions	Note 3 – Mergers and Acquisitions Proposed Merger On July 23, 2015, the Company entered into a merger agreement with Anthem, Inc. (“Anthem”) and Anthem Merger Sub Corp. (“Merger Sub”), a direct wholly-owned subsidiary of Anthem. The merger agreement provides (a) for the merger of the Company and Merger Sub, with the Company continuing as the surviving corporation and (b) if certain tax opinions are delivered, immediately following the completion of the initial merger, for the surviving corporation to be merged with and into Anthem, with Anthem continuing as the surviving corporation (collectively, the “merger”). Subject to certain terms, conditions, and customary operating covenants, each share of Cigna common stock issued and outstanding immediately prior to the effective time of the merger would be converted into the right to receive (a) $103.40 in cash, without interest, and (b) 0.5152 of a share of Anthem common stock. The closing price of Anthem common stock on February 22, 2017 was $163.27. At special shareholders' meetings held in December 2015, Cigna shareholders approved the merger and Anthem shareholders approved the issuance of shares of Anthem common stock in connection with the merger. Completing the merger remains subject to certain customary conditions, including the receipt of certain necessary governmental and regulatory approvals and the absence of a legal restraint prohibiting the merger. Completing the merger is not subject to a financing condition. On July 21, 2016, the U.S. Department of Justice (“DOJ”) and certain state attorneys general filed a civil antitrust lawsuit in the U.S. District Court for the District of Columbia (the “District Court”) seeking to block the merger and, on January 4, 2017, the parties concluded the District Court trial. On January 18, 2017, the Company received a written notice from Anthem seeking to extend the termination date of the merger agreement from January 31, 2017 to April 30, 2017. On February 8, 2017, the District Court issued an order enjoining the proposed merger. Anthem filed a notice of appeal of the District Court's order with the U.S. Court of Appeals for the District of Columbia Circuit (the “Appeals Court”) and requested an expedited appeal. On February 14, 2017, the Company delivered a notice to Anthem terminating the merger agreement and filed suit in the Delaware Court of Chancery (the “Chancery Court”) seeking, among other things, declaratory judgment that Cigna's termination of the merger agreement is lawful and that Anthem does not have the right to extend the merger agreement termination date. Later that day, Anthem filed a lawsuit in the Chancery Court against the Company seeking, among other things, a temporary restraining order to enjoin Cigna from terminating the merger agreement, specific performance and damages, and, on February 15, 2017, the Chancery Court issued an order temporarily enjoining the Company from terminating the merger agreement. This order will be subject to further review at a preliminary injunction hearing. On February 17, 2017, the Appeals Court granted Anthem's motion for an expedited appeal and set oral arguments for March 24, 2017. That same day, the Company filed its notice of appeal of the District Court's order enjoining the merger with the Appeals Court. The merger agreement contains customary covenants, including covenants that Cigna conduct its business in the ordinary course during the period between entering into the merger agreement and closing. In addition, Cigna's ability to take certain actions prior to closing without Anthem's consent is subject to certain limitations. These limitations relate to, among other matters, the payment of dividends, capital expenditures, the payment or retirement of indebtedness or the incurrence of new indebtedness, settlement of material claims or proceedings, mergers or acquisitions, and certain employment-related matters. The Company incurred pre-tax costs of $166 million ($147 million after-tax) for the year ended December 31, 2016, and $66 million ($57 million after-tax) for the year ended December 31, 2015 directly related to the proposed merger. These costs consisted primarily of fees for financial advisory, legal and other professional services. If the merger is consummated, most of the merger-related costs are not deductible for federal income tax purposes. If the merger is not consummated, most of these costs would become deductible for federal income tax purposes, resulting in a tax benefit of approximately $50 million. Acquisitions The Company completed certain acquisitions during the three years ended December 31, 2016 that were not material to the Company's results of operations, liquidity or financial condition. In accordance with GAAP, the purchase price for each acquisition was allocated to the tangible and intangible net assets acquired based on management's estimates of their fair values.

Mergers and Acquisitions

12 Months Ended

Dec. 31, 2016

Acquisitions and Dispositions [Abstract]

Note 3 – Mergers and Acquisitions

Proposed Merger

On July 23, 2015, the Company entered into a merger agreement with Anthem, Inc. (“Anthem”) and Anthem Merger Sub Corp. (“Merger Sub”), a direct wholly-owned subsidiary of Anthem.

The merger agreement provides (a) for the merger of the Company and Merger Sub, with the Company continuing as the surviving corporation and (b) if certain tax opinions are delivered, immediately following the completion of the initial merger, for the surviving corporation to be merged with and into Anthem, with Anthem continuing as the surviving corporation (collectively, the “merger”). Subject to certain terms, conditions, and customary operating covenants, each share of Cigna common stock issued and outstanding immediately prior to the effective time of the merger would be converted into the right to receive (a) $103.40 in cash, without interest, and (b) 0.5152 of a share of Anthem common stock. The closing price of Anthem common stock on February 22, 2017 was $163.27.

At special shareholders' meetings held in December 2015, Cigna shareholders approved the merger and Anthem shareholders approved the issuance of shares of Anthem common stock in connection with the merger. Completing the merger remains subject to certain customary conditions, including the receipt of certain necessary governmental and regulatory approvals and the absence of a legal restraint prohibiting the merger. Completing the merger is not subject to a financing condition.

On July 21, 2016, the U.S. Department of Justice (“DOJ”) and certain state attorneys general filed a civil antitrust lawsuit in the U.S. District Court for the District of Columbia (the “District Court”) seeking to block the merger and, on January 4, 2017, the parties concluded the District Court trial.

On January 18, 2017, the Company received a written notice from Anthem seeking to extend the termination date of the merger agreement from January 31, 2017 to April 30, 2017.

On February 8, 2017, the District Court issued an order enjoining the proposed merger. Anthem filed a notice of appeal of the District Court's order with the U.S. Court of Appeals for the District of Columbia Circuit (the “Appeals Court”) and requested an expedited appeal.

On February 14, 2017, the Company delivered a notice to Anthem terminating the merger agreement and filed suit in the Delaware Court of Chancery (the “Chancery Court”) seeking, among other things, declaratory judgment that Cigna's termination of the merger agreement is lawful and that Anthem does not have the right to extend the merger agreement termination date. Later that day, Anthem filed a lawsuit in the Chancery Court against the Company seeking, among other things, a temporary restraining order to enjoin Cigna from terminating the merger agreement, specific performance and damages, and, on February 15, 2017, the Chancery Court issued an order temporarily enjoining the Company from terminating the merger agreement. This order will be subject to further review at a preliminary injunction hearing.

On February 17, 2017, the Appeals Court granted Anthem's motion for an expedited appeal and set oral arguments for March 24, 2017. That same day, the Company filed its notice of appeal of the District Court's order enjoining the merger with the Appeals Court.

The merger agreement contains customary covenants, including covenants that Cigna conduct its business in the ordinary course during the period between entering into the merger agreement and closing. In addition, Cigna's ability to take certain actions prior to closing without Anthem's consent is subject to certain limitations. These limitations relate to, among other matters, the payment of dividends, capital expenditures, the payment or retirement of indebtedness or the incurrence of new indebtedness, settlement of material claims or proceedings, mergers or acquisitions, and certain employment-related matters.

The Company incurred pre-tax costs of $166 million ($147 million after-tax) for the year ended December 31, 2016, and $66 million ($57 million after-tax) for the year ended December 31, 2015 directly related to the proposed merger. These costs consisted primarily of fees for financial advisory, legal and other professional services. If the merger is consummated, most of the merger-related costs are not deductible for federal income tax purposes. If the merger is not consummated, most of these costs would become deductible for federal income tax purposes, resulting in a tax benefit of approximately $50 million.

Acquisitions

The Company completed certain acquisitions during the three years ended December 31, 2016 that were not material to the Company's results of operations, liquidity or financial condition. In accordance with GAAP, the purchase price for each acquisition was allocated to the tangible and intangible net assets acquired based on management's estimates of their fair values.