Note 6 - Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Book value	$ 27,391	$ 26,827
Accumulated depreciation and amortization	(18,896)	(18,144)
Net book value	8,495	8,683
Land and Building [Member]
Property, Plant and Equipment [Line Items]
Book value	11,464	11,405
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Book value	13,599	13,098
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Book value	$ 2,328	$ 2,324