Name:	ci_FeesPaidToFederalGovernmentByHealthInsurersExpected
Namespace Prefix:	ci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Monetary amount by product segment of present value of future benefits for LTD and workers' compensation to be paid to or on behalf of policyholders and related expenses less the present value of future net premiums using assumptions such as estimates of expected investment yields, mortality, morbidity, terminations and expenses, applicable at the time the insurance contracts are made and unpaid claim costs relating to insurance contracts including estimates of costs relating to incurred but not reported claims based on the estimated ultimate cost of settling the claims (including effects of inflation and other societal and economic factors), using past experience adjusted for current trends and any other factors that would modify past experience.

No definition available.

Name:	ci_LiabilityForFuturePolicyBenefitLongTermDisabiliytAndWorkersCompensationDiscountedLiabilityAmount
Namespace Prefix:	ci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Percentage discount rate at the high end of a range of reasonable estimates used to calculate present value of an expected stream of future payments for LTD and workers compensation, which is included in the calculation of the amount of the specified guaranteed benefit obligation as of the balance sheet date.

No definition available.

Name:	ci_LongDurationContractsAssumptionsLongTermDisabilityAndWorkersCompensationDiscountRateHighEnd
Namespace Prefix:	ci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage discount rate at the low end of a range of reasonable estimates used to calculate present value of an expected stream of future payments for LTD and workers compensation, which is included in the calculation of the amount of the specified guaranteed benefit obligation as of the blanace sheet date.

No definition available.

Name:	ci_LongDurationContractsAssumptionsLongTermDisabilityAndWorkersCompensationDiscountRateLowEnd
Namespace Prefix:	ci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percent likelihood a deferred tax asset will be realized, as determined by an assessment of available evidecnce, below which a valuation allowance will be recorded.

No definition available.

Name:	ci_MinimumLikelihoodDeferredTaxAssetWillBeRealized
Namespace Prefix:	ci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Period after which noncontrolling interests in joint venture may be redeemded by either party to joint venture agreement.

No definition available.

Name:	ci_MinorityInterestRedemptionTerm
Namespace Prefix:	ci_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

The percent of the total life insurance in force that is structured as a participating business.

No definition available.

Name:	ci_PercentageTotalLifeInsuranceInForceParticipatingBusiness
Namespace Prefix:	ci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percent of ASO fees reimbursed through performance guarantees

No definition available.

Name:	ci_PerformanceGuaranteePercentPayment
Namespace Prefix:	ci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percent of ASO fees at risk for repayment through performance guarantees

No definition available.

Name:	ci_PerformanceGuaranteePercentRisk
Namespace Prefix:	ci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross reinsurance premiums receivable to net realizable value.

No definition available.

Name:	ci_ReinsurancePremiumsReceivableAllowanceForDoubtfulAccounts
Namespace Prefix:	ci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	us-gaap_AccountingPoliciesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5074-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.4)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of deferred policy acquisition costs charged to expense in the period, generally in proportion to related revenue earned, estimated gross profits, or over the customer relationship or some other period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 95-1

-Paragraph 19, 20, 21, 22, 23

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 16

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.7(a))

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 7

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 60

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 18

-Article 12

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6967983&loc=d3e11264-158415

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 30

-Section 35

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=7473040&loc=d3e10157-158409

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section 45

-Paragraph 2

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6480726&loc=d3e6691-158385

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 97

-Paragraph 22, 23, 24, 25, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amortization method of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company. The straight-line method is the preferred amortization method, unless another method better reflects the pattern in which the asset is consumed.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 12, 13, 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 35

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=7658317&loc=d3e15372-109273

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph l

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 43

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 72

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph e

-Clause 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 34

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The maximum interest rate applied during the stated period to monetary deposits made by or on behalf of policyholders for contracts that may contractually vary the amount and timing of premium payments without the approval of the insurer and in which premium payments are credited to the policyholder balance, against which amounts are assessed for contract services and to which amounts are credited as income. The policyholder balance provides a base upon which interest accrues to the policyholder and, when compared with the death benefit amount, fixes the insurer's net amount at risk. The insurer can often adjust the schedule of amounts assessed for contract services and the rate at which interest is credited to the policyholder balance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 13

-Subparagraph b

-Article 7

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.13(b))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 60

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_InterestSensitiveLifeInterestRateAssumptionsHighEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The minimum interest rate applied to deposits made by or on behalf of policyholders to contracts that may contractually vary the amount and timing of premium payments without the approval of the insurer and in which premium payments are credited to the policyholder balance, against which amounts are assessed for contract services and to which amounts are credited as income. The policyholder balance provides a base upon which interest accrues to the policyholder and, when compared with the death benefit amount, fixes the insurer's net amount at risk. The insurer can often adjust the schedule of amounts assessed for contract services and the rate at which interest is credited to the policyholder balance. during the stated period.

Name:	us-gaap_InterestSensitiveLifeInterestRateAssumptionsLowEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration