Note 13 - Retirement Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Service benefit	$ (15)	$ (35)	$ (57)
Interest cost	30	52	72
Net periodic cost	$ 15	$ 17	$ 15