Note 8 - Accrued Retirement Benefits - Net Periodic Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest cost	$ 184	$ 203
Expected return on plan assets	(174)	(164)
Amortization of net loss	68	82
Pension and other postretirement expenses	$ 78	$ 121