Note 13 - Retirement Benefit Plans - Obligation and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Benefit obligation at beginning of year	$ 1,654	$ 1,782	$ 1,913
Service benefit	(15)	(35)	(57)
Interest cost	30	52	72
Benefits paid	(142)	(145)	(146)
Benefit obligation at end of year	1,527	1,654	1,782
Accumulated post-retirement benefit obligation	1,527	1,654	1,782
Fair value of plan assets	0	0	0
Accumulated post-retirement benefit obligation in excess of plan assets	1,527	1,654	1,782
Retirees [Member]
Benefit obligation at beginning of year	1,654	1,782
Benefit obligation at end of year	1,527	1,654	1,782
Accumulated post-retirement benefit obligation	1,527	1,654	1,782
Other Participants [Member]
Benefit obligation at beginning of year	0	0
Benefit obligation at end of year	0	0	0
Accumulated post-retirement benefit obligation	$ 0	$ 0	$ 0