Note 7 - Share-based Compensation - Performance Share Transactions (Details) - Performance Shares [Member]	3 Months Ended
	Mar. 31, 2022 $ / shares shares
Outstanding (in shares) | shares	193,523
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 21.50
Granted (in shares) | shares	59,578
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 19.55
Vested (in shares) | shares	(15,750)
Vested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 16.97
Outstanding (in shares) | shares	237,351
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 21.31