Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator for earnings (loss) per share calculation:
Income (loss) from continuing operations	$ 1,390	$ 1,285	$ (174)	$ 3,344
Income from continuing operations allocated to participating securities	(1)	(3)	(3)	(12)
Income from continuing operations attributable to noncontrolling interest				(1)
Income (loss) from continuing operations attributable to CVS Health	$ 1,389	$ 1,282	$ (177)	$ 3,331
Denominator for earnings per share calculation:
Weighted average shares, basic (in shares)	1,020.0	1,016.0	1,018.0	1,022.0
Effect of dilutive securities (in shares)	2.0	4.0		4.0
Weighted average shares, diluted (in shares)	1,022.0	1,020.0	1,018.0	1,026.0
Earnings (loss) per share from continuing operations:
Earnings (loss) per share, basic (in dollars per share)	$ 1.36	$ 1.26	$ (0.17)	$ 3.26
Earnings (loss) per share, diluted (in dollars per share)	$ 1.36	$ 1.26	$ (0.17)	$ 3.25
Common Equivalent Shares
Reconciliation of basic and diluted earnings per common share
Antidilutive securities excluded from computation of earnings per share (in shares)			2.0
Employee Stock Option
Reconciliation of basic and diluted earnings per common share
Antidilutive securities excluded from computation of earnings per share (in shares)	12.3	10.9	13.6	9.9