Note 5 - Employee Benefit Plan - Net Periodic Pension Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest cost	$ 36	$ 41	$ 108	$ 123
Expected return on plan assets	(174)	(157)	(522)	(471)
Recognized net actuarial (gain)/loss	9	7	27	21
Net periodic benefit cost	$ (129)	$ (109)	$ (387)	$ (327)