Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Requirements and Effects of New Accounting Guidance

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 will impact the Company.
	Effects of adoption: using the nature of distribution approach, the Company reported $144 million of cash receipts related to distributions from partnership earnings in operating activities in 2016. The Company reclassified $137 million for 2015 and $111 million for 2014 from investing to operating activities in the Consolidated Statement of Cash Flows.
Improvements to Employee Share-Based Payment Accounting (ASU 2016-09) Early adopted on January 1, 2016	Requires:
		• Excess tax benefits or deficiencies to be recorded prospectively in the income statement when awards vest or are settled; previously these effects were reported in additional paid-in capital • Cash flows related to excess tax benefits to be classified prospectively as an operating activity in the statement of cash flows (previously financing) • All cash payments made on an employee’s behalf for withheld shares to be presented retrospectively as a financing activity in the statement of cash flows • Prospective changes to the calculation of common stock equivalents for earnings per share
	Permits:
		• Repurchasing more of an employee’s shares for tax withholding purposes than previously allowed without triggering liability accounting • An accounting policy election to record forfeitures as they occur instead of estimating
	Effects of adoption:
		• $29 million of excess tax benefits recorded in net income during 2016 (in Corporate) • $72 million of tax withholding cash flows reported in financing activities in 2016; reclassified $79 million for 2015 and $53 million for 2014 of tax withholding from operating to financing activities in the Consolidated Statement of Cash Flows • Approximately one million additional weighted average shares in 2016 for the diluted earnings per share calculations • No changes in our employee tax withholding practices for stock compensation • The amount of compensation cost recognized in each period continues to be determined based on estimated forfeitures
Disclosures about Short-Duration Insurance Contracts (ASU 2015-09) Adopted December 31, 2016	Requires additional information about an insurance entity’s initial claim estimates and subsequent adjustments to those estimates; methodologies and judgments in estimating claims; and the timing, frequency and severity of claims.
	Effects of adoption:
		• See Note 7 for these disclosures about our Global Health Care medical cost payable liabilities • See Note 8 for these disclosures about our unpaid claims and claim expense liabilities
Accounting Standard and Adoption Date	Requirements and Effects of Adopting New Guidance
Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) (ASU 2015-07) Adopted January 1, 2016	Removes fair value disclosure requirement for all investments measured using the practical expedient of net asset value (“NAV”) per share. Certain additional disclosures are now required for such investments.
	Effects of adoption: see Note 10 for these disclosures about separate account investments that use NAV as a practical expedient; comparable prior year amounts are also disclosed.
Amendments to the Consolidation Analysis (ASU 2015-02) Adopted January 1, 2016	Defines limited partnerships as variable interest entities unless substantive kick-out rights or participating rights exist.
	Effects of adoption:
		• No material effect on the Company’s financial statements • See Note 13 for disclosures about various limited partnerships newly identified as variable interest entities for which the Company is not the primary beneficiary

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
Simplifying the Test for Goodwill Impairment (ASU 2017-04) Required as of January 1, 2020, with early adoption permitted as of January 1, 2017	Simplifies the accounting for goodwill impairment by eliminating the need to determine the fair value of individual assets and liabilities of a reporting unit to measure a goodwill impairment.
	Expected effects: the Company is evaluating this new standard and its expected timing of adoption.
Clarifying the Definition of a Business (ASU 2017-01) Required as of January 1, 2018, with early adoption permitted as of January 1, 2017	Revises the definition of a business and provides a more robust framework for entities to use in determining when a set of assets and activities is a business.
	Expected effects: if a group of assets acquired after adoption is not considered a business, no goodwill will be recorded and most intangible assets recorded from the acquisition will be amortized to shareholders’ net income over their useful lives. The Company is evaluating this new standard and its expected timing of adoption.
Intra-Entity Asset Transfers of Assets Other than Inventory (ASU 2016-16) Required as of January 1, 2018, with early adoption permitted as of January 1, 2017	Requires:
		• Entities to recognize the tax impacts of all intra-entity sales of assets other than inventory even though the pre-tax effects of those transactions are eliminated in consolidation • Modified retrospective approach for adoption, with a cumulative-effect adjustment recorded in retained earnings
	Expected effects: the Company is evaluating this new standard, its expected timing of adoption and effects on its financial statements and disclosures.
Accounting Standard and Effective Date Applicable for Cigna	Requirements and Expected Effects of New Guidance Not Yet Adopted
Measurement of Credit Losses on Financial Instruments (ASU 2016-13) Required as of January 1, 2020, with early adoption permitted as of January 1, 2019	Requires:
		• A new approach (based on expected credit losses) to estimate and recognize credit losses for certain financial instruments such as mortgage loans, reinsurance recoverables and other receivables • Changes in the criteria for impairment of available-for-sale debt securities • Modified retrospective approach for adoption, with a cumulative-effect adjustment recorded in retained earnings
	Expected effects: the Company is evaluating this new standard, its expected timing of adoption and effects on its financial statements and disclosures. It is possible that an additional allowance for future expected credit losses for certain financial instruments may be required at adoption.
Leases (ASU 2016-02) Required as of January 1, 2019	Requires:
		• Balance sheet recognition of assets and liabilities arising from leases, including from leases embedded in other contracts • Additional disclosures of the amount, timing and uncertainty of cash flows from leases will be required • Modified retrospective approach for leases in effect as of and after the date of adoption with a cumulative-effect adjustment recorded in retained earnings
	Expected effects: the Company is still evaluating the impact the standard could have on the Consolidated Financial Statements; however, while the Company has not yet quantified the amount, we do expect the standard will have a material impact on our Consolidated Balance Sheets due to the recognition of additional assets and liabilities for operating leases. The actual increase in assets and liabilities will depend on the volume and terms of leases in place at adoption.
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 $260 million as of December 31, 2016 will be reported at fair value at adoption • An increase to retained earnings of approximately $60 million, after-tax, if implemented as of December 31, 2016. Actual cumulative effect adjustment will depend on investments held and market conditions at adoption.

Accounting Standard and Effective Date Applicable for Cigna	Requirements and Expected Effects of New Guidance Not Yet Adopted
Revenue from Contracts with Customers (ASU 2014-09 and related amendments) Required as of January 1, 2018, with early adoption permitted as of January 1, 2017	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 • Extensive new disclosures including the presentation of additional 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 contracts but does not apply to certain contracts within the scope of other GAAP, such as insurance contracts • The Company will adopt the new guidance as of January 1, 2018 but has not yet selected a method of adoption • The Company does not currently expect the adoption of the new guidance to have a material impact to its pattern of revenue recognition
		• The Company is continuing to evaluate the new requirements. Specifically, the Company is evaluating the combination of contract guidance for certain customers where 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.