Note 9 - Employee Retirement Plans - Net Funded Status (Details) - USD ($) $ in Thousands		12 Months Ended			36 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023
Benefit obligation at beginning of the period		$ 64,273	$ 84,308	$ 88,960	$ 88,960
Interest cost		2,873	2,313	2,168
Benefits paid		(5,104)	(5,667)	(5,693)
Actuarial (gain) loss (A)	[1]	1,916	(16,681)	(1,127)
Settlement		(13,861)	0	0
Benefit obligation at end of the period		50,097	64,273	84,308	50,097
Fair value of plan assets at beginning of the period		45,378	56,779	56,495	56,495
Actual return		2,827	(7,337)	4,374
Defined Benefit Plan, Plan Assets, Contributions by Employer		1,603	1,603	1,603
Benefits paid		(5,104)	(5,667)	(5,693)
Settlement		(13,861)	0	0
Fair value of plan assets at end of the period		30,843	45,378	56,779	30,843
Unfunded status at end of the period		(19,254)	(18,895)	(27,529)
Current liabilities		(1,572)	(1,575)	(1,578)	(1,572)
Noncurrent liabilities		(17,682)	(17,320)	(25,951)	(17,682)
Net amount recognized		$ (19,254)	$ (18,895)	$ (27,529)	$ (19,254)

[1] The change in the actuarial (gain) loss for the three years ended December 31, 2023 was primarily attributable to changes in the discount rate.