Property, plant and equipment (Details) (USD $) In Millions, unless otherwise specified			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Building and Improvements [Member] Minimum [Member]	Dec. 31, 2013 Building and Improvements [Member] Maximum [Member]	Dec. 31, 2013 Manufacturing Equipment [Member] Minimum [Member]	Dec. 31, 2013 Manufacturing Equipment [Member] Maximum [Member]	Dec. 31, 2013 Laboratory Equipment [Member] Minimum [Member]	Dec. 31, 2013 Laboratory Equipment [Member] Maximum [Member]	Dec. 31, 2013 Other [Member] Minimum [Member]	Dec. 31, 2013 Other [Member] Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life			10 years	40 years	8 years	12 years	8 years	12 years	3 years	15 years
Property, plant and equipment [Abstract]
Land	$ 408	$ 412
Buildings and improvements	3,467	3,510
Manufacturing equipment	2,024	2,007
Laboratory equipment	1,165	1,056
Other	4,107	3,891
Construction in progress	1,120	1,071
Property, plant and equipment, gross	12,291	11,947
Less accumulated depreciation and amortization	(6,942)	(6,621)
Property, plant and equipment, net	$ 5,349	$ 5,326