Note 8 - Employee Retirement Plans - Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Interest cost	$ 2,462	$ 2,572	$ 2,873
Pension Plan And Supplemental Plan [Member]
Interest cost	2,462	2,572	2,873
Expected return on plan assets	(1,831)	(1,828)	(2,111)
Amortization of net actuarial gains (losses)	(240)	(94)	(146)
Settlement/curtailment gain	0	0	(2,177)
Net periodic pension cost (benefit)	$ 391	$ 650	$ (1,561)