Note 13 - Employee Benefit Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Requisite Service Period (Year)	3 years
Defined Benefit Plan, Accumulated Benefit Obligation	$ 13,200,000	$ 13,600,000
Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year	$ 255,000
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	20.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 259,000	260,000
Liability, Defined Benefit Plan, Total	2,100,000	2,000,000.0
Pension and Other Postretirement Benefits Cost (Reversal of Cost), Total	256,000	205,000
Board of Directors [Member]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 204,000	$ 143,000