Property, Plant and Equipment

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

PROPERTY, PLANT AND EQUIPMENT

	As of December 31,
(Dollars in thousands)	2017			2016
Land	$	14,620		$	15,855
Buildings and improvements	135,191			138,493
Machinery and equipment	238,000			220,238
Office equipment	56,554			54,013
	444,365			428,599
Accumulated depreciation	(289,909		)	(259,178		)
Property, plant and equipment, net	154,456			169,421
Equipment in process	25,155			7,495
Total property, plant and equipment, net	$	179,611		$	176,916

Depreciation expense was $29.3 million in 2017, $26.6 million in 2016 and $23.2 million in 2015.

In the first quarter of 2017, we completed the planned sale of a parcel of land in Belgium that had been classified as held for sale as of December 31, 2016 and recognized a gain on sale of approximately $0.9 million in operating income.

In the second quarter of 2017, we began actively marketing for sale unutilized property in the United States consisting of a building and an adjacent parcel of land with a net book value of $0.9 million. The asset is no longer being depreciated and is classified as held for sale as of December 31, 2017.

In the third quarter of 2017, we completed the sale of a facility located in Belgium and recognized a gain on sale of approximately $4.4 million in operating income.