Note 17 - Segment Information: Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands			3 Months Ended												12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Sales, net (notes 1, 3, 9 and 11)			$ 9,157	$ 10,005	$ 10,400	$ 11,340	$ 12,333	$ 12,505	$ 12,866	$ 12,520	$ 13,575	$ 12,955	$ 13,428	$ 12,323	$ 40,903	$ 50,224	$ 52,281
Gross profit			5,323	5,802	6,253	6,766	7,098	7,359	7,739	7,843	8,327	8,186	8,151	7,533	24,143	30,038	32,196
Sales and marketing															1,901	1,685	1,507
Research and development															813	560	493
Litigation Expense															2,139	1,660	670
Amortization															2,065	5,692	6,417
Operating income															13,594	16,777	19,790
Dividend and interest income															3,367	3,036	661
Income before provision for income taxes	$ 16,802	$ 20,089													16,802	20,089	20,659
Provision for income taxes (note 7)	$ 2,928	$ 3,454													2,928	3,454	4,186
Net income			$ 2,902	$ 3,563	$ 3,453	$ 3,956	$ 4,287	$ 3,935	$ 4,200	$ 4,214	$ 4,555	$ 4,280	$ 4,103	$ 3,534	13,874	16,635	16,473
Single Operating Segment
Sales, net (notes 1, 3, 9 and 11)															40,903	50,224	52,281
Standard cost of sales															13,406	17,400	16,939
Other cost of sales															3,353	2,786	3,146
Gross profit															$ 24,143	$ 30,038	$ 32,196
Gross Profit Margin															59.00%	59.80%	61.60%
Sales and marketing															$ 1,901	$ 1,685	$ 1,507
Research and development															813	560	493
Litigation Expense															2,139	1,660	670
Amortization															2,030	5,661	6,386
Other Selling, General and Administrative Expense															3,666	3,695	3,350
Operating income															$ 13,594	$ 16,777	$ 19,790
Operating Income Margin															33.20%	33.40%	37.90%
Dividend and interest income															$ 3,367	$ 3,036	$ 661
Other Operating Income (Expense), Net															(159)	276	209
Income before provision for income taxes															16,802	20,089	20,659
Provision for income taxes (note 7)															2,928	3,454	4,186
Net income															$ 13,874	$ 16,635	$ 16,473