Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Summary of Property, Plant and Equipment

Property, plant and equipment consist of the following as of December 31 (in thousands):

	2017			2016
Building and improvements	$	49,403		$	47,859
Machinery and equipment		228,107			223,450
Furniture and fixtures		1,620			2,710
Forklifts and tractors		9,799			10,167
Computer equipment		9,680			10,481
Construction in process		5,954			4,172
Land		11,417			11,417
Total property, plant and equipment		315,980			310,256
Accumulated depreciation		(212,870	)		(206,970	)
Total property, plant and equipment, net	$	103,110		$	103,286