Note 9 - Employee Benefit Plans (Details Textual) - Supplemental Employee Retirement Plan [Member] - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0.8	$ 0.8
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	0.8
Defined Benefit Plan, Benefit Obligation, Ending Balance	$ 22.5		$ 22.7