Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2018

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
Revenue from Contracts with Customers (Accounting Standards Update ("ASU") 2014-09 and related amendments)Adopted as of January 1, 2018	Requires:
	•	Revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services
	•	Additional revenue-related disclosures
	Effects of adoption:
	•	Applies to the Company’s service and mail order pharmacy contracts with customers
	•	Adopted through full retrospective restatement
	•	Cumulative effect adjustment of $24 million after-tax was recorded, reducing the December 31, 2016 balance of retained earnings. Adjustment established a contract liability for service fee revenue billed that must be deferred and allocated to services performed after a customer contract terminates. Subsequent changes in the contract liability and the related impact to net income and per share amounts since adoption were immaterial.
	•	Immaterial reclassifications were made to prior periods in the Consolidated Statements of Income to conform to the current presentation. The ASU and related interpretive guidance provide clarification on topics including whether all or a part of a contract is within its scope, and the definition of a customer. Companies are required to identify and evaluate distinct performance obligations within their contracts. These clarifications resulted in reclassifications within the Global Health Care segment affecting premiums, fees and other revenues, Global Health Care medical costs, and other operating expenses and had no impact on recognition patterns or net income.
	•	Prior period balances in the Company's footnote disclosures have been updated to reflect adjustments resulting from the adoption of this ASU.

Accounting Standard and Adoption Date	Requirements and Effects of Adopting New Guidance
Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01 and related amendments)Adopted 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
	Effects of adoption:
	•	Certain limited partnership interests previously carried at cost of approximately $200 million were increased to fair value of approximately $275 million on January 1, 2018. Subsequent changes in fair value are reported in net investment income.
	•	Changes in fair value for equity securities that have a readily determinable fair value that were previously reported in accumulated other comprehensive income are now reported in net realized investment gains.
	•	Cumulative effect adjustment of $62 million after-tax was recorded, increasing the opening balance of retained earnings in 2018.
	•	See Notes 9 and 10 for updated disclosures about equity securities.
Targeted Improvements to Accounting for Hedging Activities (ASU 2017-12)Early adopted as of January 1, 2018	Guidance:
	•	Relaxes requirements for financial and nonfinancial hedging strategies to be eligible for hedge accounting and changes how companies assess effectiveness
	•	Amends presentation and disclosure requirements to improve transparency about the uses and results of hedging programs
	Effects of adoption:
	•	An immaterial amount of retained earnings was reclassified to accumulated other comprehensive income, decreasing the opening balance in 2018, for a portion of the hedging instruments that was previously excluded from the assessment of hedge effectiveness for fair value hedges.
	•	See Note 11 for the Company's disclosures about derivatives.
Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (ASU 2018-02)Early adopted as of January 1, 2018	Guidance:
	•	Allows companies to reclassify the tax effects stranded in accumulated other comprehensive income to retained earnings as a result of H.R.1, An Act to Provide for Reconciliation Pursuant to Titles II and V of the Concurrent Resolution on the Budget for Fiscal Year 2018 (referred to throughout this Form 10-Q as "U.S. tax reform" or "U.S. tax reform legislation")
	•	Requires additional disclosures of the Company's accounting policy for releasing income tax effects from accumulated other comprehensive income
	•	Allows companies to apply the guidance retrospectively or in the period of adoption
	Effects of adoption: Accumulated other comprehensive income of $229 million was reclassified to retained earnings, increasing the opening balance in 2018. See Note 13 for additional information including accounting policy disclosures.

Accounting Guidance Not Yet Adopted
Accounting Standard and Effective Date Applicable for Cigna	Requirements and Expected Effects of Guidance Not Yet Adopted
Leases (ASU 2016-02 and related amendments)Required as of January 1, 2019	Requires:
	•	Balance sheet recognition of assets and liabilities arising from leases, including leases embedded in other contracts
	•	Additional disclosures of the amount, timing and uncertainty of cash flows from leases
	•	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 continuing to evaluate the impact this standard will have on its financial statements.
	•	While we continue to refine the estimated impact of this standard, the Company currently expects an increase to assets and liabilities of approximately $500 million. The actual increase in assets and liabilities will depend on the volume, terms and discount rates of leases in place at the time of adoption.
	•	The Company plans to elect the optional practical expedient to retain the current classification of leases, and therefore, does not anticipate a material impact to the Consolidated Statements of Income or Cash Flows.
	•	The Company is implementing a new lease system and also expects that adoption of the new standard will require changes to internal control over financial reporting.
	•	The Company intends to adopt this new guidance as of the adoption date and will not present comparative periods in the financial statements, as recently allowed.
Targeted Improvements to the Accounting for Long-Duration Contracts (ASU 2018-12)Required as of January 1, 2021	Requires (for insurance entities that issue long-duration contracts):
	•	Cash flow assumptions used to measure the liability for future policy benefits for traditional and limited-pay contract to be reconsidered at least annually with any changes reflected in net income.
	•	Discount rate assumptions to be reviewed quarterly (based on an upper-medium grade (low-credit-risk) fixed-income instrument yield that maximizes the use of observable market inputs) with any changes reflected in other comprehensive income.
	•	Deferred policy acquisition costs to be amortized on a constant-level basis over the expected term of the related contract.
	•	Fair value measurement of all market risk benefits.
	•	Additional disclosures, including liability rollforwards and information about significant inputs, judgments, assumptions and methods used in measurement.
	•	Transition methods at adoption vary.
		-	Changes to the liability for future policy benefits will use a modified retrospective approach (applied to all contracts on the basis of their carrying amounts as of the beginning of the earliest period presented), with an option to elect a full retrospective transition under certain criteria.
		-	Deferred policy acquisition costs are to be transitioned consistent with the method applied to the liability for future policyholder benefits.
		-	Market risk benefits are required to transition using retrospective application.
	Expected effects:
	•		The Company is evaluating the impact of this newly-issued guidance, but it is expected to have a significant impact on our processes, controls, systems and financial results. The new guidance will apply to insurance products predominantly sold in the Company's businesses other than the Global Health Care segment.

Receivables and Contract Liabilities from Contracts with Clients

(In millions)	September 30, 2018		December 31, 2017
Receivables, net	$	898	$	885
Contract liabilities	$	50	$	54