Note 5 - Investment Securities - Amortized Cost and Fair Value of Investment Securities Available-for-sale (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Securities available-for-sale, amortized cost	$ 227,280	$ 125,281
Securities available-for-sale, gross unrealized gains	1,064	310
Securities available-for-sale, gross unrealized losses	(2,935)	(2,008)
Securities available-for-sale, fair value	225,409	123,583
US Government Agencies Debt Securities [Member]
Securities available-for-sale, amortized cost	82,506	67,603
Securities available-for-sale, gross unrealized gains	160
Securities available-for-sale, gross unrealized losses	(2,087)	(1,715)
Securities available-for-sale, fair value	80,579	65,888
US States and Political Subdivisions Debt Securities [Member]
Securities available-for-sale, amortized cost	44,737	38,867
Securities available-for-sale, gross unrealized gains	230	255
Securities available-for-sale, gross unrealized losses	(366)	(134)
Securities available-for-sale, fair value	44,601	38,988
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available-for-sale, amortized cost	97,535	17,123
Securities available-for-sale, gross unrealized gains	582
Securities available-for-sale, gross unrealized losses	(346)	(145)
Securities available-for-sale, fair value	97,771	16,978
Equity Securities - Mutual Funds [Member]
Securities available-for-sale, amortized cost	1,000	500
Securities available-for-sale, gross unrealized gains		3
Securities available-for-sale, gross unrealized losses	(32)
Securities available-for-sale, fair value	968	503
Equity Securities [Member]
Securities available-for-sale, amortized cost	1,502	1,188
Securities available-for-sale, gross unrealized gains	92	52
Securities available-for-sale, gross unrealized losses	(104)	(14)
Securities available-for-sale, fair value	$ 1,490	$ 1,226

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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Amount, before tax, of unrealized loss 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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