Significant Accounting Policies - Description of Business (Details)		12 Months Ended
Dec. 16, 2015 clinic state pharmacy	Dec. 31, 2016 clinic Suite state Center condition Branch segment drugstore pharmacy
Segment reporting information
Number of reportable segments \| segment		3
Pharmacy Services Segment
Segment reporting information
Number of pharmacies (more than 68,000)		68,000
Number of chain pharmacies		41,000
Number of independent pharmacies		27,000
Number of conditions for integrated disease management \| condition		18
Centers of excellence for infusion and enteral services \| Center		3
Number of states pharmacies operated \| state		41
Pharmacy Services Segment \| Specialty stores
Segment reporting information
Number of pharmacies (more than 68,000)		23
Pharmacy Services Segment \| Specialty mail order
Segment reporting information
Number of pharmacies (more than 68,000)		13
Pharmacy Services Segment \| Mail service
Segment reporting information
Number of pharmacies (more than 68,000)		4
Pharmacy Services Segment \| Infusion and Enteral Branches
Segment reporting information
Number of infusion and enteral branches \| Branch		84
Pharmacy Services Segment \| Ambulatory Infusion Suites
Segment reporting information
Number of infusion and enteral branches \| Suite		73
Retail/LTC Segment
Segment reporting information
Number of states pharmacies operated \| state		49
Number of drugstores		9,709
Number of LTC spoke pharmacies \| drugstore		152
Number of LTC hub pharmacies \| drugstore		32
Retail/LTC Segment \| MinuteClinic
Segment reporting information
Number of drugstores \| clinic		1,139
Retail/LTC Segment \| Minute Clinic Within C V S Pharmacy Stores
Segment reporting information
Number of drugstores \| clinic		1,053
Retail/LTC Segment \| Minute Clinic within Target Stores
Segment reporting information
Number of drugstores \| clinic		79
Retail/LTC Segment \| Minute Clinic in Corporate Campuses or Other Locations
Segment reporting information
Number of drugstores \| clinic		7
Retail/LTC Segment \| Pharmacy
Segment reporting information
Number of drugstores		7,980
Target Pharmacy Acquisition \| Retail/LTC Segment
Segment reporting information
Number of states pharmacies operated \| state	47
Number of pharmacies acquired	1,672	1,674
Number of clinics acquired \| clinic	79

Centers of Excellence for Infusion and Enteral Services

No definition available.

Name:	cvs_CentersofExcellenceforInfusionandEnteralServices
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of conditions for which integrated disease management is available under the entity's rare disease management programs.

+ References

No definition available.

+ Details

Name:	cvs_NumberOfConditionsForIntegratedDiseaseManagement
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of drugstores operated by the entity.

+ References

No definition available.

+ Details

Name:	cvs_NumberOfDrugstores
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of pharmacies through which the reporting entity supplies pharmaceuticals.

+ References

No definition available.

+ Details

Name:	cvs_NumberOfPharmacies
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of chain pharmacies through which the reporting entity supplies pharmaceuticals.

+ References

No definition available.

+ Details

Name:	cvs_NumberofChainPharmacies
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Clinics Acquired

+ References

No definition available.

+ Details

Name:	cvs_NumberofClinicsAcquired
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of independent pharmacies through which the reporting entity supplies pharmaceuticals.

+ References

No definition available.

+ Details

Name:	cvs_NumberofIndependentPharmacies
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Infusion and Enteral Branches

+ References

No definition available.

+ Details

Name:	cvs_NumberofInfusionandEnteralBranches
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of LTC hub pharmacies

+ References

No definition available.

+ Details

Name:	cvs_NumberofLTChubpharmacies
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of LTC spoke pharmacies

+ References

No definition available.

+ Details

Name:	cvs_NumberofLTCspokepharmacies
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Pharmacies Acquired

+ References

No definition available.

+ Details

Name:	cvs_NumberofPharmaciesAcquired
Namespace Prefix:	cvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	cvs_SegmentInformationByServicesAxis=cvs_SpecialtyStoresMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	cvs_SegmentInformationByServicesAxis=cvs_SpecialtyMailOrderMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	cvs_SegmentInformationByServicesAxis=cvs_MailServiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	cvs_SegmentInformationByServicesAxis=cvs_InfusionandEnteralBranchesMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	cvs_SegmentInformationByServicesAxis=cvs_AmbulatoryinfusionsuitesMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cvs_RetailLTCSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_ProductOrServiceAxis=cvs_MinuteClinicMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_ProductOrServiceAxis=cvs_MinuteClinicWithinCVSPharmacyStoresMember
Namespace Prefix:
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- Details

Name:	us-gaap_ProductOrServiceAxis=cvs_MinuteClinicwithinTargetStoresMember
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- Details

Name:	us-gaap_ProductOrServiceAxis=cvs_MinuteClinicinCorporateCampusesorOtherLocationsMember
Namespace Prefix:
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- Details

Name:	cvs_SegmentInformationByServicesAxis=cvs_PharmacyAndOnlineWebsiteMember
Namespace Prefix:
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=cvs_TargetPharmacyAcquisitionMember
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