Note 8 - Reclassifications Out of Other Comprehensive Income - Items Reclassified to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Tax expense related to realized gains on securities sold	$ 308	$ 413	$ 687	$ 930
Net income	1,332	917	3,495	2,116
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Realized gains on sales of securities held for sale during the period consider available for sale		18	60	60
Tax expense related to realized gains on securities sold		6	13	20
Net income		$ 12	$ 47	$ 40