Goodwill and intangible assets (Identifiable Intangible Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Finite-lived intangible assets:
Gross carrying amount	$ 18,264	$ 17,905
Accumulated amortization	(8,744)	(7,279)
Intangible assets, net	9,520	10,626
Indefinite-lived intangible assets:
Identifiable intangible assets	19,023	18,920
Accumulated amortization	(8,744)	(7,279)
Identifiable intangible assets, net	10,279	11,641
IPR&D [Member]
Indefinite-lived intangible assets:
Indefinite-lived intangible assets	759	1,015
Developed product technology rights [Member]
Finite-lived intangible assets:
Gross carrying amount	12,534	12,310
Accumulated amortization	(5,947)	(4,996)
Intangible assets, net	6,587	7,314
Licensing rights [Member]
Finite-lived intangible assets:
Gross carrying amount	3,275	3,275
Accumulated amortization	(1,300)	(998)
Intangible assets, net	1,975	2,277
Marketing-related rights [Member]
Finite-lived intangible assets:
Gross carrying amount	1,333	1,186
Accumulated amortization	(793)	(650)
Intangible assets, net	540	536
R&D technology rights [Member]
Finite-lived intangible assets:
Gross carrying amount	1,122	1,134
Accumulated amortization	(704)	(635)
Intangible assets, net	$ 418	$ 499