Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, plant and equipment

Property, plant and equipment consisted of the following (dollar amounts in millions):

		December 31,
	Useful life (in years)	2017			2016
Land	—	$	283		$	295
Buildings and improvements	10-40	3,507			3,640
Manufacturing equipment	8-12	2,372			2,275
Laboratory equipment	8-12	1,179			1,092
Other	3-15	4,404			4,380
Construction in progress	—	834			745
Property, plant and equipment, gross		12,579			12,427
Less accumulated depreciation and amortization		(7,590		)	(7,466		)
Property, plant and equipment, net		$	4,989		$	4,961