Note 9 - Earnings Per Common Share - Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017		Sep. 30, 2018		Sep. 30, 2017
Earnings per common share, basic, weighted average common shares outstanding (in shares)	5,810,618	5,770,175	[1]	5,804,251	[1]	5,767,602	[1]
Earnings per common share, basic, net income	$ 1,332	$ 917		$ 3,495		$ 2,116
Earnings per common share, basic (in dollars per share)	$ 0.23	$ 0.16	[1]	$ 0.60	[1]	$ 0.37	[1]
Dilutive stock options, weighted average common shares outstanding (in shares)	50,464	24,602		50,464		24,602
Earnings per common share, diluted, weighted average common shares outstanding (in shares)	5,861,082	5,794,777	[1]	5,854,715	[1]	5,792,204	[1]
Earnings per common share, diluted, net income	$ 1,332	$ 917		$ 3,495		$ 2,116
Diluted earnings per common share (in dollars per share)	$ 0.23	$ 0.16	[1]	$ 0.60	[1]	$ 0.37	[1]
Earnings per common share, diluted (in dollars per share)	$ 0.23	$ 0.16	[1]	$ 0.60	[1]	$ 0.37	[1]

[1] Restated for the 4% stock dividend distributed July 11, 2016