Note 12 - Retirement, Savings and Deferred Compensation Plans - Components of SERP Expense (Details) - Supplemental Employee Retirement Plan [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Service cost	$ 92	$ 126
Interest cost	221	159
Net amortization	18	78
Net periodic benefit cost	$ 331	$ 363