Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Sep. 30, 2014	Dec. 31, 2014 segment
Segment reporting information
Charitable Contribution to the CVS Foundation	$ 25
Number of reportable segments		3us-gaap_NumberOfReportableSegments
Pharmacy Services Segment
Segment reporting information
Number of pharmacies		68,000
Number of Chain Pharmacies		41,000
Number of Independent Pharmacies		27,000
Number of conditions for integrated disease management		17
Number of states pharmacies operated		40
Centers of Excellence for Infusion and Enteral Services		6
Pharmacy Services Segment \| Specialty stores
Segment reporting information
Number of pharmacies		27
Pharmacy Services Segment \| Specialty mail order
Segment reporting information
Number of pharmacies		11
Pharmacy Services Segment \| Mail service
Segment reporting information
Number of pharmacies		4
Pharmacy Services Segment \| Infusion and Enteral Branches [Member]
Segment reporting information
Number of Infusion and Enteral Branches		86
Retail Pharmacy Segment
Segment reporting information
Number of states pharmacies operated		44
Number of drugstores		7,822
Retail Pharmacy Segment \| MinuteClinic within CVS Pharmacy Stores
Segment reporting information
Number of drugstores		963
Retail Pharmacy Segment \| MinuteClinic
Segment reporting information
Number of drugstores		971
Retail Pharmacy Segment \| CVS/pharmacy
Segment reporting information
Number of drugstores		7,765

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

Charitable Contribution to the CVS Foundation

+ References

No definition available.

+ Details

Name:	cvs_CharitableContributiontotheCVSFoundation
Namespace Prefix:	cvs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

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 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

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

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

- Details

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cvs_PharmacyServicesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cvs_RetailPharmacySegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: