Note 2 - Summary of Significant Accounting Policies - Weighted Average Common Shares (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Weighted average common shares outstanding - basic (in shares)	11,886,005	10,695,867	11,294,306	10,655,469
Unvested shares of restricted stock and employee stock options (in shares)	326,312	168,673	371,544	185,175
Weighted average common shares and common share equivalents outstanding - diluted (in shares)	12,212,317	10,864,540	11,665,850	10,840,644
Average number of potentially dilutive securities excluded from calculation because their effect was anti-dilutive during the period (in shares)	107,666	518,145	119,585	491,014