Segment Reporting (Details) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015 USD ($) Mail_Service_Pharmacy state drugstore pharmacy	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Mail_Service_Pharmacy state drugstore segment pharmacy	Sep. 30, 2014 USD ($)
Segment reporting information
Number of segments | segment				3
Net revenues		$ 38,644	$ 35,021	$ 112,144	$ 102,312
Gross profit		6,661	6,468	19,227	18,734
Operating profit (loss)(3)		$ 2,331	2,246	$ 6,725	6,478
Pharmacy Services Segment
Segment reporting information
Number of Centers of Excellence for Infusion and Enteral Services		6		6
Number of states pharmacies operated | state		40		40
Net revenues	[1]	$ 25,528	22,534	$ 73,849	64,566
Gross profit		1,468	1,403	3,735	3,533
Operating profit (loss)(3)		1,162	1,087	2,837	2,605
Net revenues, retail co-payments		$ 2,100	1,900	$ 6,800	6,100
Pharmacy Services Segment | Specialty stores
Segment reporting information
Number of pharmacies | pharmacy		24		24
Pharmacy Services Segment | Specialty mail order
Segment reporting information
Number of pharmacies | pharmacy		11		11
Pharmacy Services Segment | Mail service
Segment reporting information
Number of pharmacies | Mail_Service_Pharmacy		5		5
Pharmacy Services Segment | Infusion and Enteral Branches
Segment reporting information
Number of Infusion and Enteral Branches | Mail_Service_Pharmacy		83		83
Pharmacy Services Segment | Ambulatory infusion suites [Member]
Segment reporting information
Number of Infusion and Enteral Branches | Mail_Service_Pharmacy		73		73
Retail/LTC Segment [Member]
Segment reporting information
Number of states pharmacies operated | state		44		44
Number of retail drugstores | drugstore		7,911		7,911
Net revenues		$ 17,912	16,749	$ 52,105	50,100
Gross profit		5,373	5,237	15,990	15,719
Operating profit (loss)(3)		$ 1,643	1,527	$ 5,050	4,982
Number of retail drugstores operating a pharmacy | drugstore		7,852		7,852
Number of LTC spoke pharmacies | drugstore		113		113
Number of LTC hub pharmacies | drugstore		32		32
Retail/LTC Segment [Member] | MinuteClinic within CVS Pharmacy Stores
Segment reporting information
Number of clinics in retail drugstores | drugstore		1,013		1,013
Retail/LTC Segment [Member] | MinuteClinic
Segment reporting information
Number of clinics | drugstore		1,020		1,020
Retail/LTC Segment [Member] | Specialty stores
Segment reporting information
Number of pharmacies | drugstore		33		33
Intersegment Eliminations
Segment reporting information
Net revenues	[2]	$ (4,796)	(4,262)	$ (13,810)	(12,354)
Gross profit	[2]	(180)	(172)	(498)	(518)
Operating profit (loss)(3)	[2],[3]	(165)	(172)	(450)	(518)
Corporate Segment
Segment reporting information
Net revenues		0	0	0	0
Gross profit		0	0	0	0
Operating profit (loss)(3)		(309)	$ (196)	(712)	$ (591)
Business acquisition transaction costs		$ 115		$ 135

[1] Net revenues of the Pharmacy Services Segment include approximately $2.1 billion and $1.9 billion of retail co-payments for the three months ended September 30, 2015 and 2014, respectively, as well as $6.8 billion and $6.1 billion of retail co-payments for the nine months ended September 30, 2015 and 2014, respectively.

[2] Intersegment eliminations relate to intersegment revenue generating activities that occur between the Pharmacy Services Segment and the Retail/LTC Segment. These occur in the following ways: when members of Pharmacy Services Segment clients (“members”) fill prescriptions at retail stores to purchase covered products, when members enrolled in programs such as Maintenance Choice® elect to pick up maintenance prescriptions at a retail drugstore instead of receiving them through the mail, or when members have prescriptions filled at long-term care facilities. When these occur, both the Pharmacy Services and Retail/LTC segments record the revenues, gross profit and operating profit on a standalone basis.

[3] The Corporate Segment operating loss includes $115 million and $135 million of acquisition-related transaction and integration costs for the three and nine months ended September 30, 2015, respectively.