Note 4 - Periodic Pension Expense - Net Periodic Benefit Cost (Details) - Pension Plan [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Service cost - benefits earned during the period	$ 51	$ 46
Interest cost on projected benefit obligation	100	187
Expected return on plan assets	0	(358)
Recognized actuarial loss	428	600
Net periodic pension cost	$ 579	$ 475