Note 4 - Securities - Maturity of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Due in one year or less, amortized cost	$ 1,924
Due in one year or less, fair value	1,912
Due after one year through five years, amortized cost	30,077
Due after one year through five years, fair value	29,308
Due after five through ten years, amortized cost	15,305
Due after five through ten years, fair value	14,803
Due after ten years, amortized cost	4,749
Due after ten years, fair value	4,617
Securities without single maturity date, amortized cost	100,752
Securities-available for sale	97,509	$ 99,350
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities without single maturity date, amortized cost	28,526
Securities without single maturity date, fair value	27,664
Securities-available for sale	27,664	20,758
Collateralized Mortgage Obligations [Member]
Securities without single maturity date, amortized cost	20,171
Securities without single maturity date, fair value	19,205
Securities-available for sale	$ 19,205	$ 21,924

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth fiscal year through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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