Note 13 - Employee Benefit Plans - Schedule of Changes in Aggregate Actuarial Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Beginning balance	$ 11,312	$ 9,265
Plan change	0	262
Service cost	310	320	$ 245
Interest cost	355	404	358
Actuarial loss	1,217	1,570
Benefits paid	(615)	(509)
Ending balance	$ 12,579	$ 11,312	$ 9,265