Summary of Signficant Accounting Policies	6 Months Ended
Jun. 30, 2017
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Note 2 – Significant Accounting Policies Basis of Presentation The Consolidated Financial Statements include the accounts of Cigna Corporation and its subsidiaries. Intercompany transactions and accounts have been eliminated in consolidation. These Consolidated Financial Statements were prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Amounts recorded in the Consolidated Financial Statements necessarily reflect management’s estimates and assumptions about medical costs, investment valuation, interest rates and other factors. Significant estimates are discussed throughout these Notes; however, actual results could differ from those estimates. The impact of a change in estimate is generally included in earnings in the period of adjustment. Certain reclassifications may be made to prior year amounts to conform to the current presentation. These interim Consolidated Financial Statements are unaudited but include all adjustments (including normal recurring adjustments) necessary, in the opinion of management, for a fair statement of financial position and results of operations for the periods reported. The interim Consolidated Financial Statements and Notes should be read in conjunction with the Consolidated Financial Statements and Notes included in the Company’s 2016 Annual Report on Form 10-K (“2016 Form 10-K”). The preparation of interim Consolidated Financial Statements necessarily relies heavily on estimates. This and certain other factors, including the seasonal nature of portions of the health care and related benefits business, as well as competitive and other market conditions, call for caution in estimating full-year results based on interim results of operations. Recent Accounting Pronouncements The Company’s 2016 Form 10-K includes discussion of significant recent accounting pronouncements that either have impacted or may impact our financial statements in the future. The following tables provide information about recently adopted and recently issued or changed accounting guidance (applicable to Cigna) that have occurred since the Company filed its 2016 Form 10-K. Recently Adopted Accounting Guidance Accounting Standard and Adoption Date Requirements and Effects of Adopting New Guidance Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (Accounting Standards Update (“ASU”) 2016-15) Early adopted as of December 31, 2016 Specifies how certain transactions should be classified in the statement of cash flows. While the standard addresses multiple types of transactions, only a change in the treatment of distributions from equity method investments impacted the Company. Effects of adoption: using the nature of distribution approach, the Company reported $74 million of cash receipts related to distributions from partnership earnings in operating activities for the six months ended June 30, 2017. The Company reclassified $71 million of cash receipts for the six months ended June 30, 2016 from investing to operating activities in the Consolidated Statements of Cash Flows. Recently Issued Accounting Guidance Not Yet Adopted Accounting Standard and Effective Date Applicable for Cigna Requirements and Expected Effects of New Guidance Not Yet Adopted Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASU 2017-07) Required as of January 1, 2018 Requires employers to separate the service cost component from the other components of net benefit cost. Under the new guidance, only service cost is eligible for capitalization (as either deferred policy acquisition costs or capitalized software). This change in the capitalization rule is to be applied prospectively upon adoption. In addition, income statement captions used for each component of net benefit cost must be disclosed. Expected effects: the Company expects the effect of this new guidance to be immaterial to its results of operations. Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) Required as of January 1, 2018 Requires: • Entities to measure equity investments at fair value in net income if they are neither consolidated nor accounted for under the equity method • Cumulative effect adjustment to the beginning balance of retained earnings at adoption Expected effects: • Certain limited partnership interests carried at cost of $230 million as of June 30, 2017 will be reported at fair value at adoption • An increase to retained earnings of approximately $50 million, after-tax, if implemented as of June 30, 2017. Actual cumulative effect adjustment will depend on investments held and market conditions at adoption. Revenue from Contracts with Customers (ASU 2014-09 and related amendments) Required as of January 1, 2018 Requires: • Companies to estimate and allocate the expected customer contract revenues among distinct goods or services based on relative standalone selling prices • Revenues to be recognized as goods or services are delivered • New disclosures including the presentation of relevant categories of revenues and information about related contract assets and liabilities • Adoption through retrospective restatement with or without using certain practical expedients or adoption with a cumulative effect adjustment Expected effects: • Applies to the Company’s non-insurance, administrative service and mail order pharmacy contracts but does not apply to certain contracts within the scope of other GAAP, such as the Company's insurance and investment contracts accounted for under ASC 944 • The Company expects to adopt the new guidance through retrospective restatement • The Company does not expect the adoption of the new guidance to have a material impact to its pattern of revenue recognition or net income. Adoption of this new guidance could result in reclassifications within the Consolidated Statements of Income. • The Company is continuing to evaluate the new requirements. Specifically, the Company is evaluating the combination of contract guidance for certain customers when the Company provides both insurance and non-insurance products, the deferral of revenue for services provided after the termination of certain administrative contracts and the Company’s status as principal or agent for certain performance obligations.

Summary of Signficant Accounting Policies

6 Months Ended

Jun. 30, 2017

Significant Accounting Policies [Text Block]

Note 2 – Significant Accounting Policies

Basis of Presentation

The Consolidated Financial Statements include the accounts of Cigna Corporation and its subsidiaries. Intercompany transactions and accounts have been eliminated in consolidation. These Consolidated Financial Statements were prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Amounts recorded in the Consolidated Financial Statements necessarily reflect management’s estimates and assumptions about medical costs, investment valuation, interest rates and other factors. Significant estimates are discussed throughout these Notes; however, actual results could differ from those estimates. The impact of a change in estimate is generally included in earnings in the period of adjustment. Certain reclassifications may be made to prior year amounts to conform to the current presentation.

These interim Consolidated Financial Statements are unaudited but include all adjustments (including normal recurring adjustments) necessary, in the opinion of management, for a fair statement of financial position and results of operations for the periods reported. The interim Consolidated Financial Statements and Notes should be read in conjunction with the Consolidated Financial Statements and Notes included in the Company’s 2016 Annual Report on Form 10-K (“2016 Form 10-K”). The preparation of interim Consolidated Financial Statements necessarily relies heavily on estimates. This and certain other factors, including the seasonal nature of portions of the health care and related benefits business, as well as competitive and other market conditions, call for caution in estimating full-year results based on interim results of operations.

Recent Accounting Pronouncements

The Company’s 2016 Form 10-K includes discussion of significant recent accounting pronouncements that either have impacted or may impact our financial statements in the future.

The following tables provide information about recently adopted and recently issued or changed accounting guidance (applicable to Cigna) that have occurred since the Company filed its 2016 Form 10-K.

Recently Adopted Accounting Guidance

Accounting Standard and Adoption Date

Requirements and Effects of Adopting New Guidance

Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (Accounting Standards Update (“ASU”) 2016-15) Early adopted as of December 31, 2016

Specifies how certain transactions should be classified in the statement of cash flows. While the standard addresses multiple types of transactions, only a change in the treatment of distributions from equity method investments impacted the Company.

Effects of adoption: using the nature of distribution approach, the Company reported $74 million of cash receipts related to distributions from partnership earnings in operating activities for the six months ended June 30, 2017. The Company reclassified $71 million of cash receipts for the six months ended June 30, 2016 from investing to operating activities in the Consolidated Statements of Cash Flows.

Recently Issued Accounting Guidance Not Yet Adopted

Accounting Standard and Effective Date Applicable for Cigna

Requirements and Expected Effects of New Guidance Not Yet Adopted

Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASU 2017-07) Required as of January 1, 2018

Requires employers to separate the service cost component from the other components of net benefit cost. Under the new guidance, only service cost is eligible for capitalization (as either deferred policy acquisition costs or capitalized software). This change in the capitalization rule is to be applied prospectively upon adoption. In addition, income statement captions used for each component of net benefit cost must be disclosed.

Expected effects: the Company expects the effect of this new guidance to be immaterial to its results of operations.

Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) Required as of January 1, 2018

Requires:

• Entities to measure equity investments at fair value in net income if they are neither consolidated nor accounted for under the equity method • Cumulative effect adjustment to the beginning balance of retained earnings at adoption

Expected effects:

• Certain limited partnership interests carried at cost of $230 million as of June 30, 2017 will be reported at fair value at adoption • An increase to retained earnings of approximately $50 million, after-tax, if implemented as of June 30, 2017. Actual cumulative effect adjustment will depend on investments held and market conditions at adoption.

Revenue from Contracts with Customers (ASU 2014-09 and related amendments) Required as of January 1, 2018

Requires:

• Companies to estimate and allocate the expected customer contract revenues among distinct goods or services based on relative standalone selling prices • Revenues to be recognized as goods or services are delivered • New disclosures including the presentation of relevant categories of revenues and information about related contract assets and liabilities • Adoption through retrospective restatement with or without using certain practical expedients or adoption with a cumulative effect adjustment

Expected effects:

• Applies to the Company’s non-insurance, administrative service and mail order pharmacy contracts but does not apply to certain contracts within the scope of other GAAP, such as the Company's insurance and investment contracts accounted for under ASC 944 • The Company expects to adopt the new guidance through retrospective restatement • The Company does not expect the adoption of the new guidance to have a material impact to its pattern of revenue recognition or net income. Adoption of this new guidance could result in reclassifications within the Consolidated Statements of Income. • The Company is continuing to evaluate the new requirements. Specifically, the Company is evaluating the combination of contract guidance for certain customers when the Company provides both insurance and non-insurance products, the deferral of revenue for services provided after the termination of certain administrative contracts and the Company’s status as principal or agent for certain performance obligations.