Note 16 - Employee Benefits and Retirement Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended			36 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
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	$ 494	$ 457	$ 396
Defined Contribution Plan, Employer Discretionary Contribution Amount				$ 0
Deferred Compensation Plan Balance Maximum	500			500
Director [Member]
Deferred Compensation Arrangement with Individual, Compensation Expense	292	281	274
Deferred Compensation Arrangement with Individual, Recorded Liability	$ 3,800	3,800	3,700	3,800
The 2013 Plan [Member]
Deferred Compensation Period	30 days
Deferred Compensation Arrangement Monthly Installment Period	10 years
The 1993 Plan [Member] | Director [Member]
Deferred Compensation Arrangement Monthly Installment Period	15 years
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%
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Compensation Expense	$ 577	551	726
Defined Benefit Plan, Benefit Obligation	$ 3,400	$ 3,400	$ 3,500	$ 3,400
Minimum [Member]
Defined Benefit Plan Designated Payment Period	10 years
Maximum [Member]
Defined Benefit Plan Designated Payment Period	20 years