Note 11 - Share Based Compensation - Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Inducement Plan [Member]
Covered Shares (in shares)		100,000	150,000
Weighted- Average Exercise Price (in dollars per share)		$ 0.85	$ 0.85
Weighted- Average Remaining Contractual Term (Year)			7 years 8 months 1 day	8 years 8 months 1 day
Aggregate Intrinsic Value			$ 45,000	$ 57,000
Exercised / cancelled, Shares (in shares)			(50,000)
Exercised/cancelled, weighted-average exercise price (in dollars per share)			$ 0.85
Forfeited or expired, covered shares (in shares)		(100,000)
Forfeited or expired, weighted-average exercise price (in dollars per share)		$ 0.85
Covered Shares (in shares)			100,000	150,000
Weighted- Average Exercise Price (in dollars per share)			$ 0.85	$ 0.85
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value		$ 0	$ 45,000
CEO Inducement Plan [Member]
Covered Shares (in shares)		630,000	630,000
Weighted- Average Exercise Price (in dollars per share)		$ 1.9	$ 1.9
Weighted- Average Remaining Contractual Term (Year)		7 years 1 month 24 days	8 years 1 month 24 days	9 years 1 month 24 days
Covered Shares (in shares)	630,000	630,000	630,000	630,000
Weighted- Average Exercise Price (in dollars per share)	$ 1.9	$ 1.9	$ 1.9	$ 1.9
Exercisable, covered shares (in shares)	630,000	630,000
Exercisable, weighted-average exercise price (in dollars per share)	$ 1.9	$ 1.9
Exercisable, weighted average remaining contractual term (Year)		7 years 1 month 24 days
The 2008 Plan [Member]
Covered Shares (in shares)		513,100	691,162
Weighted- Average Exercise Price (in dollars per share)		$ 1.63	$ 1.53
Weighted- Average Remaining Contractual Term (Year)		3 years 3 months 7 days	2 years 1 month 28 days	2 years 7 months 6 days
Aggregate Intrinsic Value	$ 12,000	$ 12,000	$ 68,000	$ 72,000
Exercised / cancelled, Shares (in shares)			(57,500)
Exercised/cancelled, weighted-average exercise price (in dollars per share)			$ 1.07
Exercised / cancelled			$ 10,000
Forfeited or expired, covered shares (in shares)		(291,100)	(120,562)
Forfeited or expired, weighted-average exercise price (in dollars per share)		$ 2.1
Covered Shares (in shares)	222,000	222,000	513,100	691,162
Weighted- Average Exercise Price (in dollars per share)	$ 1.01	$ 1.01	$ 1.63	$ 1.53
Exercisable, covered shares (in shares)	222,000	222,000
Exercisable, weighted-average exercise price (in dollars per share)	$ 1.01	$ 1.01
Exercisable, weighted average remaining contractual term (Year)		3 years 3 months 7 days
Exercisable, aggregate intrinsic value	$ 12,000	$ 12,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value		$ 0	$ 8,000
The 2018 Plan [Member]
Covered Shares (in shares)		145,000	160,000
Weighted- Average Exercise Price (in dollars per share)		$ 0.94	$ 0.93
Weighted- Average Remaining Contractual Term (Year)		4 years 9 months 14 days	5 years 9 months 14 days	6 years 9 months 25 days
Aggregate Intrinsic Value	$ 26,000	$ 26,000	$ 52,000	$ 31,000
Exercised / cancelled, Shares (in shares)			(12,500)
Exercised/cancelled, weighted-average exercise price (in dollars per share)			$ 0.76
Forfeited or expired, covered shares (in shares)			(2,500)
Covered Shares (in shares)	145,000	145,000	145,000	160,000
Weighted- Average Exercise Price (in dollars per share)	$ 0.94	$ 0.94	$ 0.94	$ 0.93
Exercisable, covered shares (in shares)	145,000	145,000
Exercisable, weighted-average exercise price (in dollars per share)	$ 0.94	$ 0.94
Exercisable, weighted average remaining contractual term (Year)		4 years 9 months 14 days
Exercisable, aggregate intrinsic value	$ 26,000	$ 26,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 8,000
The 2020 Plan [Member]
Covered Shares (in shares)		375,000	385,000
Weighted- Average Exercise Price (in dollars per share)		$ 1.55	$ 1.55
Weighted- Average Remaining Contractual Term (Year)	2 years 1 month 6 days		3 years 1 month 6 days	4 years 1 month 6 days
Forfeited or expired, covered shares (in shares)	(20,000)		(10,000)
Covered Shares (in shares)	355,000	355,000	375,000	385,000
Weighted- Average Exercise Price (in dollars per share)	$ 1.55	$ 1.55	$ 1.55	$ 1.55
Exercisable, covered shares (in shares)	177,500	177,500
Exercisable, weighted-average exercise price (in dollars per share)	$ 1.55	$ 1.55
Exercisable, weighted average remaining contractual term (Year)	2 years 1 month 6 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value		$ 0	$ 0