Segment Reporting - Sales of Company's Products (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Sales	$ 39,498	$ 42,237	$ 44,033
Revenue for the out-license of a pipeline compound			50
Operating Segments
Segment Reporting Information [Line Items]
Sales	38,441	41,800	43,834
Operating Segments | Pharmaceutical segment
Segment Reporting Information [Line Items]
Sales	34,782	36,042	37,437
Operating Segments | Pharmaceutical segment | Zetia
Segment Reporting Information [Line Items]
Sales	2,526	2,650	2,658
Operating Segments | Pharmaceutical segment | Vytorin
Segment Reporting Information [Line Items]
Sales	1,251	1,516	1,643
Operating Segments | Pharmaceutical segment | Januvia
Segment Reporting Information [Line Items]
Sales	3,863	3,931	4,004
Operating Segments | Pharmaceutical segment | Janumet
Segment Reporting Information [Line Items]
Sales	2,151	2,071	1,829
Operating Segments | Pharmaceutical segment | NuvaRing
Segment Reporting Information [Line Items]
Sales	732	723	686
Operating Segments | Pharmaceutical segment | Implanon/Nexplanon
Segment Reporting Information [Line Items]
Sales	588	502	403
Operating Segments | Pharmaceutical segment | Dulera
Segment Reporting Information [Line Items]
Sales	536	460	324
Operating Segments | Pharmaceutical segment | Follistim AQ
Segment Reporting Information [Line Items]
Sales	383	412	481
Operating Segments | Pharmaceutical segment | PegIntron
Segment Reporting Information [Line Items]
Sales	182	381	496
Operating Segments | Pharmaceutical segment | Isentress
Segment Reporting Information [Line Items]
Sales	1,511	1,673	1,643
Operating Segments | Pharmaceutical segment | Cubicin
Segment Reporting Information [Line Items]
Sales	1,127	25	24
Operating Segments | Pharmaceutical segment | Cancidas
Segment Reporting Information [Line Items]
Sales	573	681	660
Operating Segments | Pharmaceutical segment | Invanz
Segment Reporting Information [Line Items]
Sales	569	529	488
Operating Segments | Pharmaceutical segment | Noxafil
Segment Reporting Information [Line Items]
Sales	487	402	309
Operating Segments | Pharmaceutical segment | Bridion
Segment Reporting Information [Line Items]
Sales	353	340	288
Operating Segments | Pharmaceutical segment | Primaxin
Segment Reporting Information [Line Items]
Sales	313	329	335
Operating Segments | Pharmaceutical segment | Remicade
Segment Reporting Information [Line Items]
Sales	1,794	2,372	2,271
Operating Segments | Pharmaceutical segment | Simponi
Segment Reporting Information [Line Items]
Sales	690	689	500
Operating Segments | Pharmaceutical segment | Keytruda
Segment Reporting Information [Line Items]
Sales	566	55	0
Operating Segments | Pharmaceutical segment | Emend
Segment Reporting Information [Line Items]
Sales	535	553	507
Operating Segments | Pharmaceutical segment | Temodar
Segment Reporting Information [Line Items]
Sales	312	350	708
Operating Segments | Pharmaceutical segment | Singulair
Segment Reporting Information [Line Items]
Sales	931	1,092	1,196
Operating Segments | Pharmaceutical segment | Nasonex
Segment Reporting Information [Line Items]
Sales	858	1,099	1,335
Operating Segments | Pharmaceutical segment | Clarinex
Segment Reporting Information [Line Items]
Sales	187	232	235
Operating Segments | Pharmaceutical segment | Cozaar/Hyzaar
Segment Reporting Information [Line Items]
Sales	667	806	1,006
Operating Segments | Pharmaceutical segment | Arcoxia
Segment Reporting Information [Line Items]
Sales	471	519	484
Operating Segments | Pharmaceutical segment | Fosamax
Segment Reporting Information [Line Items]
Sales	359	470	560
Operating Segments | Pharmaceutical segment | Zocor
Segment Reporting Information [Line Items]
Sales	217	258	301
Operating Segments | Pharmaceutical segment | Propecia
Segment Reporting Information [Line Items]
Sales	183	264	283
Operating Segments | Pharmaceutical segment | Gardasil/Gardasil 9
Segment Reporting Information [Line Items]
Sales	1,908	1,738	1,831
Operating Segments | Pharmaceutical segment | ProQuad/M-M-R II/Varivax
Segment Reporting Information [Line Items]
Sales	1,505	1,394	1,306
Operating Segments | Pharmaceutical segment | Zostavax
Segment Reporting Information [Line Items]
Sales	749	765	758
Operating Segments | Pharmaceutical segment | RotaTeq
Segment Reporting Information [Line Items]
Sales	610	659	636
Operating Segments | Pharmaceutical segment | Pneumovax 23
Segment Reporting Information [Line Items]
Sales	542	746	653
Operating Segments | Pharmaceutical segment | Other pharmaceutical
Segment Reporting Information [Line Items]
Sales	4,553	5,356	6,596
Operating Segments | Other segments
Segment Reporting Information [Line Items]
Sales	3,659	5,758	6,397
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Sales	$ 1,057	437	$ 199
Saphris
Segment Reporting Information [Line Items]
Proceeds from sale of intangible assets		$ 232