Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share	8.1	0.1
Numerators for earnings per common share calculations:
Income from continuing operations	$ 956	$ 776
Net loss attributable to noncontrolling interest	0	1
Income from continuing operations attributable to CVS Caremark	956	777
Loss from discontinued operations, net of tax	0	(1)
Net income attributable to CVS Caremark	$ 956	$ 776
Denominators for earnings per common share calculations:
Weighted average common shares, basic (in shares)	1,232	1,299
Effect of dilutive securities:
Stock options (in shares)	7	9
Restricted stock units (in shares)	2	1
Weighted average common shares, diluted (in shares)	1,241	1,309
Basic earnings per common share:
Income from continuing operations attributable to CVS Caremark (usd per share)	$ 0.78	$ 0.60
Loss from discontinued operations attributable to CVS Caremark (usd per share)	$ 0.00	$ 0.00
Net income attributable to CVS Caremark (usd per share)	$ 0.78	$ 0.60
Diluted earnings per common share:
Income from continuing operations attributable to CVS Caremark (usd per share)	$ 0.77	$ 0.59
Loss from discontinued operations attributable to CVS Caremark (usd per share)	$ 0.00	$ 0.00
Net income attributable to CVS Caremark (in dollars per share)	$ 0.77	$ 0.59