Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Summary of Carrying Values of Property, Plant and Equipment

The carrying values of property, plant and equipment were as follows: 

	December 31,
	2018			2017
	(In thousands)
Land and land improvements	$	30,173		$	31,963
Buildings and leasehold improvements	141,009			148,598
Machinery and equipment	569,359			543,594
Computer equipment and software	139,773			136,509
Construction in process	64,145			46,898
Gross property, plant and equipment	944,459			907,562
Accumulated depreciation	(578,489		)	(570,240		)
Net property, plant and equipment	$	365,970		$	337,322