CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales	$ 23,800	$ 33,730	$ 56,111	$ 64,907
Cost of sales	16,434	22,791	38,314	44,344
Gross margin	7,366	10,939	17,797	20,563
Selling, general and administrative expense	4,997	5,317	10,408	10,650
Operating income	2,369	5,622	7,389	9,913
Interest income	370	828	977	1,664
Income before taxes	2,739	6,450	8,366	11,577
Provision for income taxes	674	1,555	2,030	2,696
Net income	$ 2,065	$ 4,895	$ 6,336	$ 8,881
Basic and diluted net income per common share	$ 0.17	$ 0.39	$ 0.51	$ 0.71
Basic and diluted weighted average shares outstanding	12,446	12,439	12,445	12,437