Goodwill and Other Intangibles - Other Intangibles (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	$ 50,131	$ 50,084
Accumulated Amortization	35,948	32,779
Net	14,183	17,305
IPR&D
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	1,194	1,653
Net	1,194	1,653
Products and product rights
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	46,693	46,269
Accumulated Amortization	34,950	31,919
Net	11,743	14,350
Tradenames
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	209	215
Accumulated Amortization	97	89
Net	112	126
Other
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	2,035	1,947
Accumulated Amortization	901	771
Net	$ 1,134	$ 1,176