Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment Disclosure [Abstract]

Property, Plant and Equipment

Estimated useful lives in years are generally as follows:

Description	Estimated Useful Life
Buildings and improvements	20-35
Laboratory and manufacturing equipment	4-10
Office and computer equipment	3-7
Leasehold improvements	Shorter of useful life or lease term

Property, plant and equipment is summarized as follows (in millions):

	December 31,
	2016			2015
Land	$	394		$	393
Buildings and improvements (including leasehold improvements)	1,713			1,320
Laboratory and manufacturing equipment	469			377
Office and computer equipment	466			395
Construction in progress	641			554
Subtotal	3,683			3,039
Less accumulated depreciation and amortization	(818		)	(763		)
Total	$	2,865		$	2,276