Note 14 - Related Party Transactions (Details Textual) - Stellartech Research Corporation [Member]		3 Months Ended		6 Months Ended		160 Months Ended
	Jun. 01, 2006	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) shares	Jun. 30, 2021 USD ($)	Sep. 30, 2019	Dec. 31, 2021 USD ($)
Stock Issued During Period, Shares, New Issues (in shares) | shares				38
Related Party Transaction, Amounts of Transaction		$ 0	$ 77,000	$ 0	$ 154,000
Due to Related Parties, Total		$ 0		$ 0			$ 0
Electricity, Generation [Member]
Development and Manufacturing Agreement, Number of Units	300
Development and Manufacturing Agreement, Number of Units Purchased						855