Segment Information - Financial Data by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Sales to external customers	$ 43,316	$ 36,995	$ 123,133	$ 108,585
Operating income	2,124	1,726	8,516	7,029
Interest expense, net	168	469	722	1,463
Other (income) expense, net	(35)	40	2	52
Consolidated income before income taxes	1,991	1,217	7,792	5,514
Assets	123,017		123,017		$ 110,749
United States Segment
Sales to external customers	36,656	32,780	105,576	95,178
Operating income	1,189	1,381	6,442	5,942
Assets	107,396		107,396		98,578
Canada Segment
Sales to external customers	3,373	1,775	8,175	5,402
Operating income	600	280	1,173	746
Assets	7,546		7,546		6,168
Europe Segment
Sales to external customers	3,287	2,440	9,382	8,005
Operating income	335	$ 65	901	$ 341
Assets	$ 8,075		$ 8,075		$ 6,003