Note 9 - Income Taxes - Reconciliation of Expected Income Tax Expense With Reported Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Computed "expected" income tax expense	$ 3,929	$ 7,135	$ 6,613
Tax impact of enacted change in tax rate		1,560
Tax-exempt interest income	(1,255)	(2,144)	(2,234)
Nondeductible interest expense	69	89	92
Other, net	(183)	(347)	(519)
Total income tax expense	$ 2,560	$ 6,293	$ 3,952