Note 6 - Goodwill and Intangible Assets - Definite-lived Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net Carrying Amount	$ 3,000	$ 7,000
Patents and Trademarks [Member]
Weighted Average Amortization Period (Year)	2 years	3 years
Gross Carrying Amount	$ 474,000	$ 474,000
Accumulated Amortization	(471,000)	(467,000)
Net Carrying Amount	$ 3,000	$ 7,000