Note 11 - Income Taxes - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Federal statutory rate	21.00%	21.00%
State tax, net of federal benefit	0.50%	0.00%
Deferred correction – State net operating losses	(0.80%)	0.00%
FASB Interpretation No. 48 unrecognized tax benefits	0.00%	(4.90%)
State tax credits true-up	0.00%	(4.70%)
Permanent differences	0.00%	(4.30%)
Valuation allowance decrease	(19.80%)	(16.20%)
Other, net	(0.90%)	5.30%
Effective income tax rate	0.00%	(3.80%)