Note 8 - Stock-based Incentive Plans - Restricted Stock Activity (Details) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Balance (in shares) | shares	566,272
Balance, weighted avg. price (in dollars per share) | $ / shares	$ 7.21
Vested (in shares) | shares	(95,008)
Vested, wtd. avg. price (in dollars per share) | $ / shares	$ 7.27
Balance (in shares) | shares	471,264
Balance, weighted avg. price (in dollars per share) | $ / shares	$ 7.19