Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, plant and equipment

Summary of property, plant and equipment

	December 31,
	2018		2017
Land	$	2,378	$	2,378
Land improvements	4,357		4,357
Leasehold improvements		4,079		4,183
Buildings	28,238		26,846
Machinery and equipment	50,129		44,618
Furniture and fixtures	16,360		13,681
Mobile equipment and other	4,883		4,576
Construction-in-process	3,084		4,320
Total property, plant and equipment	113,508		104,959
Less accumulated depreciation	(58,313)		(50,997)
Net property, plant and equipment	$	55,195	$	53,962