Note 11 - Stock-based Compensation - Non-cash Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based compensation	$ 2,083	$ 1,810	$ 4,328	$ 3,570
Share-Based Payment Arrangement, Option [Member]
Share-based compensation	924	1,087	1,901	2,207
Restricted Stock Units (RSUs) [Member]
Share-based compensation	822	690	1,707	1,293
Performance Restricted Stock Unit [Member]
Share-based compensation	$ 337	$ 33	$ 720	$ 70