Note 8 - Income Taxes - Effective Tax Rate Based Upon Total Income Tax Provision (Benefit) From Continuing Operations (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Federal statutory rate	21.00%	21.00%
Permanent non-taxable income	(3.50%)	0.20%
Business credits	21.30%	2.80%
State taxes, net of federal benefit	0.00%	(0.10%)
Valuation allowance	(38.70%)	(68.60%)
Other	(0.60%)	(0.10%)
Effective Income Tax Rate Reconciliation, Percent	(0.50%)	(44.80%)