Note 13 - Employee Benefit Plans - Components of Periodic Pension Costs and Other Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest cost	$ 395	$ 443
Expected return on plan assets	(699)	(626)
Amortization of prior service beneft and net loss	268	252
Net periodic pension cost	(36)	69
Amortization of prior service benefit and net loss	(268)	(252)
Net loss	871	742
Total recognized in other comprehensive loss	603	490
Total recognized in net periodic benefit and other comprehensive loss	$ 567	$ 559