Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, plant and equipment

Summary of property, plant and equipment

	December 31,
	2020		2019
Land	$	2,378	$	2,378
Land improvements	4,830		4,541
Leasehold improvements		4,087		4,087
Buildings	29,580		28,715
Machinery and equipment	61,154		55,238
Furniture and fixtures	19,782		17,918
Mobile equipment and other	5,200		5,285
Construction-in-process	11,751		6,555
Total property, plant and equipment	138,762		124,717
Less accumulated depreciation	(74,442)		(66,273)
Net property, plant and equipment	$	64,320	$	58,444