CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Net sales	$ 41,151	$ 42,050
Cost of sales	28,447	29,970
Gross margin	12,704	12,080
Selling, general and administrative expense	5,664	5,774
Operating income	7,040	6,306
Interest income	947	214
Income before income taxes	7,987	6,520
Provision for income taxes	1,919	1,536
Net income	6,068	4,984
Other comprehensive loss, marketable securities adjustment:
Unrealized net loss arising during year	(30)
Comprehensive income	6,038	4,984
Net income - basic	16,110	13,437
Net income - diluted	$ 16,110	$ 13,437
Net income per basic share	$ 0.49	$ 0.40
Net income per diluted share	$ 0.49	$ 0.40
Weighted average shares outstanding - basic	12,307	12,381
Weighted average shares outstanding - diluted	12,307	12,381