Note 3 - Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Due in one year or less, available for sale, amortized cost	$ 4,602
Due in one year or less, available for sale, fair value	4,591
Due in one year or less, held to maturity, amortized cost	89
Due in one year or less, held to maturity, fair value	89
Due in over one to five years, available for sale, amortized cost	6,027
Due in over one to five years, available for sale, fair value	5,999
Due in over one to five years, held to maturity, amortized cost	6,839
Due in over one to five years, held to maturity, fair value	7,101
Due in over five to ten years, available for sale, amortized cost	3,060
Due in over five to ten years, available for sale, fair value	3,052
Due in over five to ten years, held to maturity, amortized cost	8,415
Due in over five to ten years, held to maturity, fair value	8,862
Due after ten years, available for sale, amortized cost
Due after ten years, available for sale, fair value
Due after ten years, held to maturity, amortized cost	3,258
Due after ten years, held to maturity, fair value	3,274
Agency mortgage-backed securities, residential, available for sale, amortized cost	89,044
Agency mortgage-backed securities, residential, available for sale, fair value	89,055
Agency mortgage-backed securities, residential, held to maturity, amortized cost	4
Agency mortgage-backed securities, residential, held to maturity, fair value	4
Total debt securities, available for sale, amortized cost	102,733
Total debt securities, available for sale, fair value	102,697
Total debt securities, held to maturity, amortized cost	18,605	$ 18,665
Securities held to maturity	$ 19,330	$ 19,171