Note 12 - Stock-based Compensation Plan - Unvested Stock Activity (Details) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2022 $ / shares shares
Unvested shares outstanding (in shares) | shares	262,533
Unvested shares outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 7.16
Granted, number of shares (in shares) | shares	79,489
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 10.03
Vested, number of shares (in shares) | shares	(18,467)
Vested, weighted average exercise price (in dollars per share) | $ / shares	$ 9.21
Forfeited, number of shares (in shares) | shares	0
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Unvested shares outstanding (in shares) | shares	323,555
Unvested shares outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 7.69