Note 7 - Share-based Compensation - Shared-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-based compensation expense	$ 1,340	$ 1,242	$ 2,420	$ 2,454
Stock Options and SARs [Member]
Share-based compensation expense	390	381	699	741
Restricted Stock [Member]
Share-based compensation expense	767	985	1,357	1,604
Performance Shares [Member]
Share-based compensation expense	$ 183	$ (124)	$ 364	$ 109