Note 2 - Investment Securities - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Securities available-for-sale, amortized cost	$ 50,560	$ 55,523
Securities available-for-sale, gross unrealized gains	182	404
Securities available-for-sale, gross unrealized losses	(1,171)	(583)
Securities available for sale, at fair value	49,571	55,344
US Government Agencies Debt Securities [Member]
Securities available-for-sale, amortized cost	12,565	13,475
Securities available-for-sale, gross unrealized gains	27	61
Securities available-for-sale, gross unrealized losses	(186)	(101)
Securities available for sale, at fair value	12,406	13,435
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available-for-sale, amortized cost	22,191	24,344
Securities available-for-sale, gross unrealized gains	1	12
Securities available-for-sale, gross unrealized losses	(767)	(375)
Securities available for sale, at fair value	21,425	23,981
Corporate Debt Securities [Member]
Securities available-for-sale, amortized cost	6,641	6,991
Securities available-for-sale, gross unrealized gains	38	118
Securities available-for-sale, gross unrealized losses	(61)	(42)
Securities available for sale, at fair value	6,618	7,067
US States and Political Subdivisions Debt Securities [Member]
Securities available-for-sale, amortized cost	9,163	10,713
Securities available-for-sale, gross unrealized gains	116	213
Securities available-for-sale, gross unrealized losses	(157)	(65)
Securities available for sale, at fair value	$ 9,122	$ 10,861

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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