Note 7 - Other Assets (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Liability, Defined Benefit Plan, Noncurrent	$ 19,876	$ 18,522
Cash Surrender Value, Fair Value Disclosure	15,100	13,900
Increase (Decrease) in Cash Surrender Value	1,300	(2,200)
Investments Held in Rabbi Trust [Member]
Debt Securities, Available-for-Sale, Amortized Cost	300	100
Debt Securities, Available-for-Sale	300	100
Supplemental Employee Retirement Plan [Member]
Liability, Defined Benefit Plan, Noncurrent	19,500	18,200
Investments, Fair Value Disclosure	$ 15,400	$ 14,000