Segment information (Revenues by Product) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues [Abstract]
Product sales	$ 5,569	$ 5,453	$ 5,574	$ 5,199	$ 5,663	$ 5,516	$ 5,474	$ 5,239	$ 21,795	$ 21,892	$ 20,944
Other revenues									1,054	1,099	718
Total revenues									22,849	22,991	21,662
ENBREL [Member]
Revenues [Abstract]
Product sales									5,433	5,965	5,364
Neulasta [Member]
Revenues [Abstract]
Product sales									4,534	4,648	4,715
Aranesp [Member]
Revenues [Abstract]
Product sales									2,053	2,093	1,951
Prolia [Member]
Revenues [Abstract]
Product sales									1,968	1,635	1,312
Sensipar Mimpara [Member]
Revenues [Abstract]
Product sales									1,718	1,582	1,415
XGEVA [Member]
Revenues [Abstract]
Product sales									1,575	1,529	1,405
EPOGEN [Member]
Revenues [Abstract]
Product sales									1,096	1,282	1,856
Kyprolis [Member]
Revenues [Abstract]
Product sales									835	692	512
Vectibix [Member]
Revenues [Abstract]
Product sales									642	611	549
Nplate [Member]
Revenues [Abstract]
Product sales									642	584	525
NEUPOGEN [Member]
Revenues [Abstract]
Product sales									549	765	1,049
Repatha [Member]
Revenues [Abstract]
Product sales									319	141	10
BLINCYTO [Member]
Revenues [Abstract]
Product sales									175	115	77
Other [Member]
Revenues [Abstract]
Product sales									$ 256	$ 250	$ 204