Note 15 - Employee Benefits and Retirement Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended		24 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Mar. 31, 2019
Defined Contribution Plan Employer Matching Contribution Percentage of Deferred Salar	100.00%
Defined Contribution Plan Maximum Annual Employee Contribution Percentage of Deferred Salar	3.00%
Defined Contribution Plan Employer Matching Contribution Percentage of Deferred Salary One	50.00%
Defined Contribution Plan Maximum Annual Employee Contribution Percentage of Deferred Salary One	2.00%
Defined Contribution Plan, Cost	$ 627	$ 549
Defined Contribution Plan, Employer Discretionary Contribution Amount			$ 0
Deferred Compensation Plan Balance Maximum	500		500
Director [Member]
Deferred Compensation Arrangement with Individual, Compensation Expense	324	309
Deferred Compensation Arrangement with Individual, Recorded Liability	$ 3,900	3,900	3,900
The 2013 Plan [Member]
Deferred Compensation Period	30 days
Deferred Compensation Arrangement Monthly Installment Period	10 years
The 1993 Plan [Member]
Deferred Compensation Arrangement Monthly Installment Period	10 years
The 1993 Plan [Member] | Director [Member]
Deferred Compensation Arrangement with Individual Compensation Interest Rate	10.00%
The 1993 Plan [Member] | Director [Member] | Prime Rate [Member]
Deferred Compensation Arrangement with Individual Compensation Interest Rate	3.00%
Merchants Holding Company [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities, Salary Continuation Liability				$ 968
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Compensation Expense	$ 547	532
Defined Benefit Plan, Benefit Obligation, Ending Balance	$ 4,700	$ 3,500	$ 4,700
Minimum [Member]
Defined Benefit Plan Designated Payment Period	10 years