Property, Plant and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, Plant and Equipment

Property, plant and equipment, net is comprised of the following (in millions):

	December 31,
	2018			2017
Buildings	$	57		$	54
Land	7			8
Machinery and equipment	204			233
Furniture and office equipment	18			19
Software and computer equipment	161			235
Leasehold improvements	75			69
Projects in progress	24			23
	546			641
Less accumulated depreciation	(297		)	(377		)
Property, plant and equipment, net	$	249		$	264

Depreciation expense was $78 million, $79 million and $75 million for the years ended December 31, 2018, 2017 and 2016, respectively. The reduction in gross cost and accumulated depreciation balances is due to a significant level of substantially depreciated asset retirements in the current year.