Segment information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Product sales	$ 3,907	$ 3,877	$ 3,893	$ 3,618	$ 3,760	$ 3,759	$ 3,613	$ 3,528	$ 15,295	$ 14,660	$ 14,351
Other revenues									287	393	291
Total revenues									15,582	15,053	14,642
Neulasta [Member] | United States [Member]
Revenues:
Product sales									3,006	2,654	2,527
Neulasta [Member] | International [Member]
Revenues:
Product sales									946	904	828
NEUPOGEN [Member] | United States [Member]
Revenues:
Product sales									959	932	901
NEUPOGEN [Member] | International [Member]
Revenues:
Product sales									301	354	387
ENBREL [Member] | United States [Member]
Revenues:
Product sales									3,458	3,304	3,283
ENBREL [Member] | Canada [Member]
Revenues:
Product sales									243	230	210
Aranesp [Member] | United States [Member]
Revenues:
Product sales									986	1,103	1,251
Aranesp [Member] | International [Member]
Revenues:
Product sales									1,317	1,383	1,401
EPOGEN [Member] | United States [Member]
Revenues:
Product sales									2,040	2,524	2,569
Sensipar [Member] | United States [Member]
Revenues:
Product sales									518	459	429
Sensipar (Mimpara) [Member] | International [Member]
Revenues:
Product sales									290	255	222
Vectibix [Member] | United States [Member]
Revenues:
Product sales									122	115	97
Vectibix [Member] | International [Member]
Revenues:
Product sales									200	173	136
Nplate [Member] | United States [Member]
Revenues:
Product sales									163	129	78
Nplate [Member] | International [Member]
Revenues:
Product sales									134	100	32
Prolia [Member] | United States [Member]
Revenues:
Product sales									130	26	0
Prolia [Member] | International [Member]
Revenues:
Product sales									73	7	0
XGEVA [Member] | United States [Member]
Revenues:
Product sales									343	8	0
XGEVA [Member] | International [Member]
Revenues:
Product sales									8	0	0
Other [Member] | International [Member]
Revenues:
Product sales									$ 58	$ 0	$ 0