Note 12 - Retirement Plans and Other Postretirement Benefits - Components of the Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pension and postretirement income	$ (36,000)	$ (36,000)
Pension Plan [Member] | UNITED STATES
Service cost	3	3
Interest cost	27	29
Expected return on plan assets	(62)	(64)
Prior service cost	3	2
Actuarial gain	(9)	(7)
Net pension (income) expense before special termination benefits	(38)	(37)
Special termination benefits	1	0
Pension and postretirement income	(37)	(37)
Pension Plan [Member] | Foreign Plan [Member]
Service cost	1	1
Interest cost	5	5
Expected return on plan assets	(5)	(5)
Prior service cost	0	0
Actuarial gain	0	0
Net pension (income) expense before special termination benefits	1	1
Special termination benefits	0	0
Pension and postretirement income	$ 1	$ 1