Note 13 - Income Taxes - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Statutory U.S. federal income tax rate	21.00%	21.00%
State and local income taxes, net of federal income tax benefit	3.30%	(6.60%)
Permanent differences	(0.60%)	1.90%
Change in valuation allowance	(26.30%)	29.20%
Equity compensation	0.00%	14.50%
Other	(2.10%)	0.20%
State NOL deferred adjustment	4.30%	0.00%
PPP loan forgiveness	0.00%	(59.60%)
Effective income tax rate	(0.40%)	0.60%