Note 2 - Investment Securities - Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Securities available for sale, amortized cost	$ 258,632	$ 273,878
Securities available for sale, gross unrealized gains	495	1,275
Securities available for sale, gross unrealized losses	7,689	3,981
Securities available for sale, fair value	251,438	271,172
Securities held to maturity, amortized cost		1
Securities held to maturity, gross unrealized gains
Securities held to maturity, gross unrealized losses
Securities held to maturity, fair value		1
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available for sale, amortized cost	105,294	114,902
Securities available for sale, gross unrealized gains	1
Securities available for sale, gross unrealized losses	4,754	2,253
Securities available for sale, fair value	100,541	112,649
Securities held to maturity, amortized cost		1
Securities held to maturity, gross unrealized gains
Securities held to maturity, gross unrealized losses
Securities held to maturity, fair value		1
Agency Collateralized Mortgage Obligations [Member]
Securities available for sale, amortized cost	23,168	15,660
Securities available for sale, gross unrealized gains	5	1
Securities available for sale, gross unrealized losses	511	338
Securities available for sale, fair value	22,662	15,323
US Government Agencies Debt Securities [Member]
Securities available for sale, amortized cost	70,477	70,013
Securities available for sale, gross unrealized gains
Securities available for sale, gross unrealized losses	1,481	985
Securities available for sale, fair value	68,996	69,028
Municipal Notes [Member]
Securities available for sale, amortized cost	59,693	73,303
Securities available for sale, gross unrealized gains	489	1,274
Securities available for sale, gross unrealized losses	943	405
Securities available for sale, fair value	$ 59,239	$ 74,172

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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