Note 7 - Accrued Retirement Benefits - Changes in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2022	Aug. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Benefit obligations			$ 16,537	$ 40,182
Interest cost			783	1,034
Actuarial gain			(580)	(7,772)
Benefits paid			(1,188)	(16,907)
Benefit obligations			15,552	16,537
Fair value of plan assets			13,783	32,103
Actual return on plan assets			1,137	(7,241)
Defined Benefit Plan, Plan Assets, Contributions by Employer		$ 5,700	128	5,828
Benefits paid	$ (14,500)		(1,188)	(16,907)
Fair value			13,860	13,783
Funded status			(1,692)	(2,754)
Accumulated benefit obligations			(15,552)	(16,537)
Accumulated benefit obligations			$ 15,552	$ 16,537
Expected long-term return on plan assets			5.25%	5.00%
Minimum [Member]
Discount rate			4.90%	5.11%
Maximum [Member]
Discount rate			4.95%	5.14%