Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net sales	$ 154,424	$ 129,366	$ 117,232
Cost of sales	53,042	44,748	37,379
Gross profit	101,382	84,618	79,853
Sales and marketing	27,655	23,700	30,339
General and administrative	25,501	22,501	19,055
Research and development	11,801	10,099	9,276
Gains on sale of building, acquisitions and divestitures	0	(470)	0
Total operating expenses	64,957	55,830	58,670
Income from operations	36,425	28,788	21,183
Other income (expense):
Interest income	197	207	698
Interest expense	(2,219)	(1,310)	0
Foreign currency loss	(116)	(329)	(202)
Income before income taxes	34,287	27,356	21,679
Provision for income taxes	7,380	6,136	3,745
Net income	$ 26,907	$ 21,220	$ 17,934
Earnings per share of common stock:
Basic (in dollars per share)	$ 1.27	$ 1.05	$ 0.91
Diluted (in dollars per share)	$ 1.25	$ 1.04	$ 0.88
Weighted-average shares outstanding:
Basic (in shares)	21,157	20,246	19,813
Diluted (in shares)	21,475	20,479	20,326
Cash dividends declared per common share (in dollars per share)	$ 0.44	$ 0.38	$ 0.34