Note 3 - Investment Securities - Schedule of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Available for sale, at amortized cost	$ 204,979	$ 190,803
Available for sale, gross unrealized gains	1,605	696
Available for sale, gross unrealized losses	(1,192)	(3,023)
Available for sale securities, at fair value	205,392	188,476
Held to maturity, at amortized cost	42,879	26,977
Held to maturity, gross unrealized gains	234	16
Held to maturity, gross unrealized losses	(667)	(1,903)
Held to maturity securities, fair value	42,446	25,090
US Treasury and Government [Member]
Available for sale, at amortized cost	4,999	5,657
Available for sale, gross unrealized gains		5
Available for sale, gross unrealized losses	(26)	(31)
Available for sale securities, at fair value	4,973	5,631
US States and Political Subdivisions Debt Securities [Member]
Available for sale, at amortized cost	94,028	88,276
Available for sale, gross unrealized gains	900	343
Available for sale, gross unrealized losses	(456)	(1,569)
Available for sale securities, at fair value	94,472	87,050
Held to maturity, at amortized cost	42,879	26,977
Held to maturity, gross unrealized gains	234	16
Held to maturity, gross unrealized losses	(667)	(1,903)
Held to maturity securities, fair value	42,446	25,090
Collateralized Mortgage Backed Securities [Member]
Available for sale, at amortized cost	100,952	96,870
Available for sale, gross unrealized gains	485	348
Available for sale, gross unrealized losses	(710)	(1,423)
Available for sale securities, at fair value	100,727	$ 95,795
Corporate Debt Securities [Member]
Available for sale, at amortized cost	5,000
Available for sale, gross unrealized gains	220
Available for sale, gross unrealized losses
Available for sale securities, at fair value	$ 5,220

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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