Note 6 - Accrued Retirement Benefits - Net Periodic Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension and other benefits:
Interest cost	$ 1,237	$ 1,633
Expected return on plan assets	(1,680)	(2,020)
Recognized net actuarial loss	933	839
Settlement expense	4,252	0
Pension expense	4,742	452
Other changes in plan assets and benefit obligations recognized in comprehensive income:
Net loss (gain)	(865)	1,739
Amortization of recognized loss	(5,185)	(839)
Total recognized (gain) loss in comprehensive income	$ (6,050)	$ 900