Note 20 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Income Tax Expense (Benefit)	$ (2)	$ 57
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Deferred Tax Assets, Valuation Allowance	$ 107,734	$ 98,840
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0
State and Local Jurisdiction [Member]
Income Tax Expense (Benefit)	2	3
Operating Loss Carryforwards	241,652	202,887
Operating Loss Carryforwards, Subject to Expiration	241,652
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	6,255	5,829
Foreign Tax Jurisdiction [Member]
Income Tax Expense (Benefit)	(4)	54
Domestic Tax Jurisdiction [Member]
Operating Loss Carryforwards	284,368	247,802
Operating Loss Carryforwards, Subject to Expiration	12,256
Operating Loss Carryforwards, Not Subject to Expiration	272,112
Domestic Tax Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 8,203	$ 7,591