Note 9 - Accrued Retirement Benefits - Net Periodic Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Interest cost	$ 264	$ 309	$ 793	$ 927
Expected return on plan assets	(306)	(418)	(918)	(1,254)
Amortization of net loss	156	225	468	675
Pension and other postretirement expenses	$ 114	$ 116	$ 343	$ 348