Note 13 - Retirement Plans and Other Postretirement Benefits - Components of the Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension income			$ (109,000)	$ (64,000)
Pension Plan [Member] | UNITED STATES
Service cost	$ 3	$ 3	10	9
Interest cost	29	24	87	56
Expected return on plan assets	(64)	(45)	(192)	(133)
Prior service cost (credit)	3	0	6	(3)
Actuarial (gain) loss	(8)	0	(22)	0
Net pension (income) expense before special termination benefits	(37)	(18)	(111)	(71)
Special termination benefits	0	1		1
Pension income	(37)	(17)	(111)	(70)
Pension Plan [Member] | Foreign Plan [Member]
Service cost	0	0	1	2
Interest cost	5	2	15	6
Expected return on plan assets	(5)	(3)	(15)	(10)
Prior service cost (credit)	0	0	0	0
Actuarial (gain) loss	0	3	1	8
Net pension (income) expense before special termination benefits	0	2	2	6
Special termination benefits	0	0	0	0
Pension income	$ 0	$ 2	$ 2	$ 6