CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 34,556	$ 28,426	$ 106,733	$ 84,537
Cost of sales	23,634	21,098	73,470	59,412
Gross margin	10,922	7,328	33,263	25,125
Selling, general and administrative expense	5,791	5,246	16,557	15,654
Operating income	5,131	2,082	16,706	9,471
Interest income	289	360	945	1,337
Income before income taxes	5,420	2,442	17,651	10,808
Provision for income taxes	1,288	610	4,214	2,640
Net income	$ 4,132	$ 1,832	$ 13,437	$ 8,168
Basic and diluted net income per common share	$ 0.33	$ 0.15	$ 1.08	$ 0.66
Basic and diluted weighted average shares outstanding	12,406	12,451	12,417	12,447