Note 19 - Revisions of Previously Issued Unaudited Consolidated Financial Statements (Unaudited) - Stockholders' Equity Statement (Details) - USD ($)	3 Months Ended						12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Balance (in shares)			12,226,306			13,115,341	12,226,306	13,115,341
Balance	$ 61,121,000	$ 60,986,000	$ 60,758,000	$ 61,949,000	$ 62,419,000	$ 61,751,000	$ 60,758,000	$ 61,751,000
Net income	1,430,000	1,146,000	552,000	503,000	693,000	1,522,000	$ 4,189,000	$ 3,282,000
Common stock repurchased and retired (in shares)							(951,010)	(910,700)
Common stock repurchased and retired	(1,049,000)	(1,097,000)	(833,000)	(1,116,000)	(960,000)	(756,000)	$ (4,002,000)	$ (3,882,000)
Stock-based compensation expense	24,000	22,000	22,000	32,000	32,000	55,000	$ 170,000	$ 147,000
Options exercised (in shares)							140,916	21,665
Options exercised	36,000	54,000	350,000	30,000	30,000		$ 464,000	$ 80,000
Total comprehensive income	(152,000)	21,000	137,000	(137,000)	(265,000)	(153,000)	4,241,000	$ 2,662,000
Treasury stock excise tax	(19,000)	(11,000)					$ (40,000)
Balance (in shares)							11,416,212	12,226,306
Balance	61,391,000	61,121,000	60,986,000	61,261,000	61,949,000	62,419,000	$ 61,568,000	$ 60,758,000
Previously Reported [Member]
Balance	61,121,000	60,986,000	60,758,000	61,949,000	62,419,000	61,751,000	$ 60,758,000	61,751,000
Net income	1,430,000	1,146,000	552,000	503,000	693,000	1,522,000
Common stock repurchased and retired	(1,049,000)	(1,097,000)	(833,000)	(1,116,000)	(960,000)	(756,000)
Stock-based compensation expense	24,000	22,000	22,000	32,000	32,000	55,000
Options exercised	36,000	54,000	350,000	30,000	30,000
Total comprehensive income	(152,000)	21,000	137,000	(137,000)	(265,000)	(153,000)
Treasury stock excise tax	(19,000)	(11,000)
Balance	$ 61,391,000	$ 61,121,000	$ 60,986,000	$ 61,261,000	$ 61,949,000	$ 62,419,000		$ 60,758,000
Common Stock [Member]
Balance (in shares)	11,875,556	12,135,556	12,226,306	12,728,173	12,945,341	13,115,341	12,226,306	13,115,341
Balance	$ 119,000	$ 122,000	$ 123,000	$ 128,000	$ 130,000	$ 132,000	$ 123,000	$ 132,000
Net income	$ 0	$ 0		$ 0	$ 0	$ 0
Common stock repurchased and retired (in shares)	(249,110)	(275,000)	(200,000)	(259,200)	(225,500)	(170,000)	(951,010)	(910,700)
Common stock repurchased and retired	$ (2,000)	$ (3,000)	$ (2,000)	$ (2,000)	$ (2,000)	$ (2,000)	$ (10,000)	$ (9,000)
Stock-based compensation expense	$ 0	$ 0	$ 0	$ 0	$ 0	0		$ 0
Options exercised (in shares)	10,000	15,000	109,250	8,332	8,332		140,916	21,665
Options exercised	$ 0	$ 0	$ 1,000	$ 0	$ 0			$ 0
Total comprehensive income	0	0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Treasury stock excise tax	$ 0	$ 0
Balance (in shares)	11,636,446	11,875,556	12,135,556	12,477,305	12,728,173	12,945,341	11,416,212	12,226,306
Balance	$ 117,000	$ 119,000	$ 122,000	$ 126,000	$ 128,000	$ 130,000	$ 114,000	$ 123,000
Common Stock [Member] | Previously Reported [Member]
Balance (in shares)	11,875,556	12,135,556	12,226,306	12,728,173	12,945,341	13,115,341	12,226,306	13,115,341
Balance	$ 119,000	$ 122,000	$ 123,000	$ 128,000	$ 130,000	$ 132,000	$ 123,000	$ 132,000
Net income	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Common stock repurchased and retired (in shares)	(249,110)	(275,000)	(200,000)	(259,200)	(225,500)	(170,000)
Common stock repurchased and retired	$ (2,000)	$ (3,000)	$ (2,000)	$ (2,000)	$ (2,000)	$ (2,000)
Stock-based compensation expense	$ 0	$ 0	$ 0	$ 0	$ 0	0
Options exercised (in shares)	10,000	15,000	109,250	8,332	8,332
Options exercised	$ 0	$ 0	$ 1,000	$ 0	$ 0
Total comprehensive income	0	0	$ 0	$ 0	$ 0	$ 0
Treasury stock excise tax	$ 0	$ 0
Balance (in shares)	11,636,446	11,875,556	12,135,556	12,477,305	12,728,173	12,945,341		12,226,306
Balance	$ 117,000	$ 119,000	$ 122,000	$ 126,000	$ 128,000	$ 130,000		$ 123,000
Additional Paid-in Capital [Member]
Balance	16,865,000	17,190,000	17,099,000	17,700,000	17,951,000	18,131,000	17,099,000	18,131,000
Net income	0	0		0	0	0
Common stock repurchased and retired	(354,000)	(390,000)	(280,000)	(360,000)	(313,000)	(235,000)	(1,330,000)	(1,259,000)
Stock-based compensation expense	24,000	22,000	22,000	32,000	32,000	55,000	170,000	147,000
Options exercised	36,000	54,000	349,000	30,000	30,000		463,000	80,000
Total comprehensive income	0	0	0	0	0	0	0	0
Treasury stock excise tax	(19,000)	(11,000)					(40,000)
Balance	16,552,000	16,865,000	17,190,000	17,402,000	17,700,000	17,951,000	16,339,000	17,099,000
Additional Paid-in Capital [Member] | Previously Reported [Member]
Balance	0	0	0	0	0	0	0	0
Net income	0	0	0	0	0	0
Common stock repurchased and retired	(41,000)	(65,000)	(371,000)	(62,000)	(62,000)	(55,000)		(227,000)
Stock-based compensation expense	24,000	22,000	22,000	32,000	32,000	55,000
Options exercised	36,000	54,000	349,000	30,000	30,000
Total comprehensive income	0	0	0	0	0	0
Treasury stock excise tax	(19,000)	(11,000)
Balance	0	0	0	0	0	0		0
Retained Earnings [Member]
Balance	45,468,000	45,026,000	45,025,000	45,408,000	45,360,000	44,357,000	45,025,000	44,357,000
Net income	1,430,000	1,146,000	552,000	503,000	693,000	1,522,000
Common stock repurchased and retired	(693,000)	(704,000)	(551,000)	(754,000)	(645,000)	(519,000)	(2,662,000)	(2,614,000)
Stock-based compensation expense	0	0	0	0	0	0	0	0
Options exercised	0	0	0	0	0			0
Total comprehensive income	0	0	0	0	0	0	4,189,000	3,282,000
Treasury stock excise tax	0	0
Balance	46,205,000	45,468,000	45,026,000	45,157,000	45,408,000	45,360,000	46,552,000	45,025,000
Retained Earnings [Member] | Previously Reported [Member]
Balance	62,333,000	62,216,000	62,124,000	63,108,000	63,311,000	62,488,000	62,124,000	62,488,000
Net income	1,430,000	1,146,000	552,000	503,000	693,000	1,522,000
Common stock repurchased and retired	(1,006,000)	(1,029,000)	(460,000)	(1,052,000)	(896,000)	(699,000)		(3,646,000)
Stock-based compensation expense	0	0	0	0	0	0
Options exercised	0	0	0	0	0
Total comprehensive income	0	0	0	0	0	0
Treasury stock excise tax	0	0
Balance	62,757,000	62,333,000	62,216,000	62,559,000	63,108,000	63,311,000		62,124,000
AOCI Attributable to Parent [Member]
Balance	(1,331,000)	(1,352,000)	(1,489,000)	(1,287,000)	(1,022,000)	(869,000)	(1,489,000)	(869,000)
Net income	0	0		0	0	0
Common stock repurchased and retired	0	0	0	0	0	0		0
Stock-based compensation expense	0	0	0	0	0	0	0	0
Options exercised	0	0	0	0	0		0	0
Total comprehensive income	(152,000)	21,000	137,000	(137,000)	(265,000)	(153,000)	52,000	(620,000)
Treasury stock excise tax	0	0
Balance	(1,483,000)	(1,331,000)	(1,352,000)	(1,424,000)	(1,287,000)	(1,022,000)	(1,437,000)	(1,489,000)
AOCI Attributable to Parent [Member] | Previously Reported [Member]
Balance	(1,331,000)	(1,352,000)	(1,489,000)	(1,287,000)	(1,022,000)	(869,000)	$ (1,489,000)	(869,000)
Net income	0	0	0	0	0	0
Common stock repurchased and retired	0	0	0	0	0	0
Stock-based compensation expense	0	0	0	0	0	0
Options exercised	0	0	0	0	0
Total comprehensive income	(152,000)	21,000	137,000	(137,000)	(265,000)	(153,000)
Treasury stock excise tax	0	0
Balance	$ (1,483,000)	$ (1,331,000)	$ (1,352,000)	$ (1,424,000)	$ (1,287,000)	$ (1,022,000)		$ (1,489,000)