Note 10 - Shareholders' Equity - Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Unvested, number of shares (in shares)	34,614	164,697
Unvested, weighted average award price (in dollars per share)	$ 2.72	$ 1.48
Granted, number of shares (in shares)	83,221	90,343
Granted, weighted average award price (in dollars per share)	$ 3.25	$ 2.72
Vested, number of shares (in shares)	(72,726)	(199,311)
Vested, weighted average award price (in dollars per share)	$ 3.00	$ 1.83
Forfeited, number of shares (in shares)	0	(21,115)
Forfeited, weighted average award price (in dollars per share)	$ 0	$ 1.48
Unvested, number of shares (in shares)	45,109	34,614
Unvested, weighted average award price (in dollars per share)	$ 3.25	$ 2.72
Expected to vest, number of shares (in shares)	45,109
Expected to vest, weighted average award price (in dollars per share)	$ 3.25