Note 13 - Retirement Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Service benefit	$ (56)	$ (19)	$ (15)
Interest cost	70	38	30
Net periodic cost	$ 14	$ 19	$ 15