Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share
Common stock outstanding but not included in the calculation of diluted earnings per share (in shares)	0.1	25.7
Numerator for earnings per common share calculation:
Income from continuing operations (in dollars)	$ 776	$ 709
Net loss attributable to noncontrolling interest	1	1
Income from continuing operations attributable to CVS Caremark, basic (in dollars)	777	710
Income (loss) from discontinued operations, net of tax	(1)	3
Net income attributable to CVS Caremark	$ 776	$ 713
Denominator for earnings per common share calculation:
Weighted average common shares, basic	1,299	1,362
Effect of dilutive securities:
Stock options (in shares)	9	7
Restricted stock units (in shares)	1	2
Weighted average common shares, diluted	1,309	1,371
Basic earnings per common share:
Income from continuing operations attributable to CVS Caremark (in dollars per share)	$ 0.60	$ 0.52
Net income attributable to CVS Caremark (in dollars per share)	$ 0.60	$ 0.52
Income (loss) from discontinued operations attributable to CVS Caremark (in dollars per share)	$ 0
Diluted earnings per common share:
Income from continuing operations attributable to CVS Caremark (in dollars per share)	$ 0.59	$ 0.52
Net income attributable to CVS Caremark (in dollars per share)	$ 0.59	$ 0.52
Income (loss) from discontinued operations attributable to CVS Caremark (in dollars per share)	$ 0