Property, Plant and Equipment

12 Months Ended

Dec. 31, 2018

Property Plant And Equipment [Abstract]

Property, Plant and Equipment

6. Property, Plant and Equipment

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

	As of December 31,
	2018			2017
Land	$	28.0		$	29.0
Building and equipment		1,885.6			1,838.5
Capitalized software costs		425.8			421.6
Instruments		2,950.5			2,683.9
Construction in progress		147.2			110.7
		5,437.1			5,083.7
Accumulated depreciation		(3,421.7	)		(3,045.1	)
Property, plant and equipment, net	$	2,015.4		$	2,038.6

Depreciation expense was $442.6 million, $454.1 million and $466.7 million for the years ended December 31, 2018, 2017 and 2016, respectively.