Note 11 - Equity Incentive Plan - Restricted Stock Activity (Details) - Restricted Stock Units (RSUs) [Member]	3 Months Ended
	Mar. 31, 2022 $ / shares shares
Outstanding, shares (in shares) | shares	412,658
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 36.33
Granted (in shares) | shares	420,452
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 25.75
Vested, shares (in shares) | shares	(87,953)
Vested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 35.19
Forfeited and cancelled, shares (in shares) | shares	(32,376)
Forfeited and cancelled, weighted average grant date fair value (in dollars per share) | $ / shares	$ 35.27
Outstanding, shares (in shares) | shares	712,781
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 30.28