Note 9 - Accrued Retirement Benefits - Net Periodic Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Interest cost	$ 203	$ 264
Expected return on plan assets	(164)	(306)
Amortization of net loss	82	156
Pension and other postretirement expenses	$ 121	$ 114