Note 14 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ 18,982,000	$ 11,752,000
Income (Loss) from Continuing Operations before Income Taxes, Foreign	63,000	60,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	3,779,000,000	$ (284,000)
Domestic Tax Authority [Member]
Operating Loss Carryforwards	121,101,000
Operating Loss Carryforwards, Subject to Expiration	89,104,000
Operating Loss Carryforwards, Not Subject to Expiration	31,997,000
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	1,478,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	54,441,000
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 1,516,000