Segment Information - Financial Data by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Sales to external customers	$ 47,923	$ 43,316	$ 136,295	$ 123,133
Operating income	2,961	2,124	9,717	8,516
Interest expense, net	(228)	(168)	(671)	(722)
Other (expense) income, net	(68)	35	3,295	(2)
Consolidated income before income taxes	2,665	1,991	12,341	7,792
Assets	141,431		141,431		$ 129,868
United States Segment
Sales to external customers	41,060	36,656	113,948	105,576
Operating income	2,425	1,189	7,231	6,442
Assets	122,620		122,620		113,831
Canada Segment
Sales to external customers	3,585	3,373	10,907	8,175
Operating income	418	600	1,452	1,173
Assets	9,294		9,294		7,432
Europe Segment
Sales to external customers	3,278	3,287	11,440	9,382
Operating income	118	$ 335	1,034	$ 901
Assets	$ 9,517		$ 9,517		$ 8,605