Note 2 - Revised Prior Period Financial Statements - Revised Financial Statements (Details) - USD ($)		3 Months Ended							6 Months Ended			9 Months Ended			12 Months Ended
		Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022		Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022		Jun. 30, 2021	Sep. 30, 2022		Sep. 30, 2021	Dec. 31, 2022		Dec. 31, 2021
Net Income		$ 503,000	$ 693,000	$ 1,522,000		$ 766,000	$ 1,671,000	$ 3,719,000	$ 2,215,000		$ 5,390,000	$ 2,718,000		$ 6,156,000	$ 3,282,000		$ 6,756,000
Balance as of December 31, 2020 (in shares)				13,115,341					13,115,341			13,115,341			13,115,341
Balance as of December 31, 2020		61,949,000	62,419,000,000	$ 61,751,000		61,460,000	60,901,000,000	58,757,000	$ 61,751,000		58,757,000	$ 61,751,000		58,757,000	$ 61,751,000		58,757,000
Cash and cash equivalents															16,290,000		16,307,000
Other comprehensive loss- foreign currency translation loss		(137,000)	(265,000)	(152,000)		(187,000)	79,000	(108,000)	(417,000)		(29,000)	(554,000)		(216,000)	(620,000)		(96,000)
Total comprehensive income (loss)		366,000	428,000	1,370,000		579,000	1,750,000	3,611,000	1,798,000		5,361,000	2,164,000		5,940,000	$ 2,662,000		$ 6,660,000
Common stock repurchased and retired (in shares)															(910,700)		(439,000)
Common stock repurchased and retired															$ (3,882,000)		$ (4,408,000)
Accounts receivable, net of allowance for doubtful accounts of $45,000 as of December 31, 2022 and $64,000 as of December 31, 2021															5,382,000		3,397,000
Accounts receivable, related party															$ 1,591,000		$ 1,383,000
Options exercised (in shares)															21,665		134,494
Options exercised															$ 80,000		$ 427,000
Inventories															24,397,000		24,969,000
Prepaid expenses															4,902,000		6,943,000
Share-based compensation expense															147,000		315,000
Total current assets															52,562,000		52,999,000
Property and equipment, net															5,742,000		6,064,000
Goodwill															55,000		55,000
Definite-lived intangible assets, net															$ 1,000		$ 3,000
Balance (in shares)															12,226,306		13,115,341
Balance		61,261,000	61,949,000	62,419,000,000		61,739,000	61,460,000	60,901,000,000	61,949,000		61,460,000	61,261,000		61,739,000	$ 60,758,000		$ 61,751,000
Right-of-use assets															1,725,000		2,648,000
Equity investment in unconsolidated affiliate		4,783,000	4,932,000	5,147,000,000		5,183,000	5,257,000	4,990,000,000	4,932,000		5,257,000	4,783,000		5,183,000	4,718,000		5,251,000
Total assets		65,081,000	66,694,000	66,747,000,000		67,025,000	66,804,000	67,573,000,000	66,694,000		66,804,000	65,081,000		67,025,000	64,803,000		67,020,000
Accounts payable															674,000		528,000
Accrued liabilities															833,000		1,250,000
Lease liabilities															899,000		883,000
Total current liabilities															2,406,000		2,661,000
Lease liabilities, net of current portion															875,000		1,817,000
Deferred income tax liabilities, net															764,000		791,000
Total liabilities															4,045,000		5,269,000
Commitments and Contingencies
Common stock, $.01 par value: 50,000,000 shares authorized; 12,226,306 and 13,115,341 shares outstanding as of December 31, 2022 and December 31, 2021, respectively															123,000		132,000
Retained earnings		62,559,000	63,108,000	63,311,000,000		62,596,000	62,130,000	61,648,000,000	63,108,000		62,130,000	62,559,000		62,596,000	62,124,000		62,488,000
Accumulated other comprehensive loss		(1,424,000)	(1,287,000)	(1,022,000,000)		(989,000)	(802,000)	(881,000,000)	(1,287,000)		(802,000)	(1,424,000)		(989,000)	(1,489,000)		(869,000)
Total shareholders' equity		61,261,000	61,949,000	62,419,000,000		61,739,000	61,460,000	60,901,000,000	61,949,000		61,460,000	61,261,000		61,739,000	60,758,000		61,751,000
Total liabilities and shareholders' equity		65,081,000	66,694,000	$ 66,747,000,000		67,025,000	66,804,000	$ 67,573,000,000	$ 66,694,000		$ 66,804,000	$ 65,081,000		$ 67,025,000	$ 64,803,000		$ 67,020,000
Common Stock [Member]
Balance as of December 31, 2020 (in shares)				13,115,341				13,419,847	13,115,341		13,419,847	13,115,341		13,419,847	13,115,341		13,419,847
Balance as of December 31, 2020				$ 132,000				$ 135,000	$ 132,000		$ 135,000	$ 132,000		$ 135,000	$ 132,000		$ 135,000
Total comprehensive income (loss)																	$ 0
Common stock repurchased and retired (in shares)															(910,700)		(439,000)
Common stock repurchased and retired															$ (9,000)		$ (4,000)
Options exercised (in shares)															21,665		134,494
Options exercised																	$ 1,000
Share-based compensation expense																	$ 0
Balance (in shares)															12,226,306		13,115,341
Balance															$ 123,000		$ 132,000
Total shareholders' equity															123,000		132,000
Additional Paid-in Capital [Member]
Balance as of December 31, 2020				0				409,000	0		409,000	0		409,000	0		409,000
Total comprehensive income (loss)															0		0
Common stock repurchased and retired															(227,000)		(1,150,000)
Options exercised															80,000		426,000
Share-based compensation expense															147,000		315,000
Balance															0		0
Total shareholders' equity															0		0
Retained Earnings [Member]
Balance as of December 31, 2020				62,488,000				58,986,000	62,488,000		58,986,000	62,488,000		58,986,000	62,488,000		58,986,000
Total comprehensive income (loss)															3,282,000		6,756,000
Common stock repurchased and retired															(3,646,000)		(3,254,000)
Options exercised																	0
Share-based compensation expense																	0
Balance															62,124,000		62,488,000
Total shareholders' equity															62,124,000		62,488,000
AOCI Attributable to Parent [Member]
Balance as of December 31, 2020	[1]			(869,000)				(773,000)	(869,000)		(773,000)	(869,000)		(773,000)	(869,000)		(773,000)
Total comprehensive income (loss)															(620,000)		(96,000)	[1]
Common stock repurchased and retired															0		0	[1]
Options exercised	[1]																0
Share-based compensation expense	[1]																0
Balance															(1,489,000)		(869,000)	[1]
Total shareholders' equity															(1,489,000)		(869,000)	[1]
Previously Reported [Member]
Net Income		503,000	693,000	1,522,000		766,000	1,671,000	3,719,000	2,215,000		5,390,000	2,718,000		6,156,000			6,756,000
Balance as of December 31, 2020		63,236,000	63,441,000,000	62,620,000		62,262,000	61,782,000,000		62,620,000			62,620,000			62,620,000
Cash and cash equivalents																	16,307,000
Other comprehensive loss- foreign currency translation loss		0	0	0		0	0	0	0		0	0		0			0
Total comprehensive income (loss)		503,000	693,000	1,522,000		766,000	1,671,000	3,719,000	2,215,000		5,390,000	2,718,000		6,156,000			6,756,000
Accounts receivable, net of allowance for doubtful accounts of $45,000 as of December 31, 2022 and $64,000 as of December 31, 2021																	3,397,000
Accounts receivable, related party																	1,383,000
Inventories																	24,969,000
Prepaid expenses																	6,943,000
Total current assets																	52,999,000
Property and equipment, net																	6,064,000
Goodwill																	55,000
Definite-lived intangible assets, net																	3,000
Balance		62,685,000	63,236,000	63,441,000,000		62,728,000	62,262,000	61,782,000,000	63,236,000		62,262,000	62,685,000		62,728,000			62,620,000
Right-of-use assets																	2,648,000
Equity investment in unconsolidated affiliate		6,207,000	6,219,000	6,169,000,000		6,172,000	6,059,000	5,871,000,000	6,219,000		6,059,000	6,207,000		6,172,000			6,120,000
Total assets		66,505,000	67,981,000	67,769,000,000		68,014,000	67,606,000	68,454,000,000	67,981,000		67,606,000	66,505,000		68,014,000			67,889,000
Accounts payable																	528,000
Accrued liabilities																	1,250,000
Lease liabilities																	883,000
Total current liabilities																	2,661,000
Lease liabilities, net of current portion																	1,817,000
Deferred income tax liabilities, net																	791,000
Total liabilities																	5,269,000
Common stock, $.01 par value: 50,000,000 shares authorized; 12,226,306 and 13,115,341 shares outstanding as of December 31, 2022 and December 31, 2021, respectively																	132,000
Retained earnings		62,559,000	63,108,000	63,311,000,000		62,596,000	62,130,000	61,648,000,000	63,108,000		62,130,000	62,559,000		62,596,000			62,488,000
Accumulated other comprehensive loss		0	0	0		0	0	0	0		0	0		0			0
Total shareholders' equity		62,685,000	63,236,000	63,441,000,000		62,728,000	62,262,000	61,782,000,000	63,236,000		62,262,000	62,685,000		62,728,000			62,620,000
Total liabilities and shareholders' equity		66,505,000	67,981,000	67,769,000,000		68,014,000	67,606,000	68,454,000,000	67,981,000		67,606,000	66,505,000		68,014,000			67,889,000
Revision of Prior Period, Adjustment [Member]
Net Income		0	0	0		0	0	0	0		0	0		0			0
Balance as of December 31, 2020		(1,287,000)	(1,022,000,000)	(869,000)	[2]	(802,000)	(881,000,000)		(869,000)	[2]		(869,000)	[2]		$ (869,000)	[2]
Cash and cash equivalents	[2]																0
Other comprehensive loss- foreign currency translation loss		(137,000)	(265,000)	(152,000)		(187,000)	79,000	(108,000)	(417,000)		(29,000)	(554,000)		(216,000)			(96,000)
Total comprehensive income (loss)		(137,000)	(265,000)	(152,000)		(187,000)	79,000	(108,000)	(417,000)		(29,000)	(554,000)		(216,000)			(96,000)
Accounts receivable, net of allowance for doubtful accounts of $45,000 as of December 31, 2022 and $64,000 as of December 31, 2021	[2]																0
Accounts receivable, related party	[2]																0
Inventories	[2]																0
Prepaid expenses	[2]																0
Total current assets	[2]																0
Property and equipment, net	[2]																0
Goodwill	[2]																0
Definite-lived intangible assets, net	[2]																0
Balance		(1,424,000)	(1,287,000)	(1,022,000,000)		(989,000)	(802,000)	(881,000,000)	(1,287,000)		(802,000)	(1,424,000)		(989,000)			(869,000)	[2]
Right-of-use assets	[2]																0
Equity investment in unconsolidated affiliate		(1,424,000)	(1,287,000)	(1,022,000,000)		(989,000)	(802,000)	(881,000,000)	(1,287,000)		(802,000)	(1,424,000)		(989,000)			(869,000)	[2]
Total assets		(1,424,000)	(1,287,000)	(1,022,000,000)		(989,000)	(802,000)	(881,000,000)	(1,287,000)		(802,000)	(1,424,000)		(989,000)			(869,000)	[2]
Accounts payable	[2]																0
Accrued liabilities	[2]																0
Lease liabilities	[2]																0
Total current liabilities	[2]																0
Lease liabilities, net of current portion	[2]																0
Deferred income tax liabilities, net	[2]																0
Total liabilities	[2]																0
Common stock, $.01 par value: 50,000,000 shares authorized; 12,226,306 and 13,115,341 shares outstanding as of December 31, 2022 and December 31, 2021, respectively	[2]																0
Retained earnings		0	0	0		0	0	0	0		0	0		0			0	[2]
Accumulated other comprehensive loss		(1,424,000)	(1,287,000)	(1,022,000,000)		(989,000)	(802,000)	(881,000,000)	(1,287,000)		(802,000)	(1,424,000)		(989,000)			(869,000)	[2]
Total shareholders' equity		(1,424,000)	(1,287,000)	(1,022,000,000)		(989,000)	(802,000)	(881,000,000)	(1,287,000)		(802,000)	(1,424,000)		(989,000)			(869,000)	[2]
Total liabilities and shareholders' equity		$ (1,424,000)	$ (1,287,000)	$ (1,022,000,000)		$ (989,000)	$ (802,000)	$ (881,000,000)	$ (1,287,000)		$ (802,000)	$ (1,424,000)		$ (989,000)			$ (869,000)	[2]

[1] This was previously reported as $0 and the total column has also been updated for this change to AOCL.

[2] Equity investment in unconsolidated affiliate and accumulated other comprehensive loss have been adjusted by a total of $869,000, of which $773,000 pertains to periods prior to 2021 and $96,000 pertains to 2021.