Note 2 - Investment Securities - Investment Securities (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Investment securities available for sale, amortized cost	$ 190,369,000	$ 243,948,000
Investment securities available for sale, gross unrealized gains	2,996,000	4,987,000
Investment securities available for sale, gross unrealized losses	759,000	640,000
Investment securities available for sale, at fair value	192,606,119	248,294,725
Investment securities held to maturity	509,617	508,456
Securities held to maturity, gross unrealized gains	1,000	2,000
Securities held to maturity, gross unrealized losses	0	0
Securities held to maturity, at fair value	511,000	510,000
US Government Agencies Debt Securities [Member]
Investment securities available for sale, amortized cost	16,797,000	30,850,000
Investment securities available for sale, gross unrealized gains	245,000	541,000
Investment securities available for sale, gross unrealized losses	47,000	6,000
Investment securities available for sale, at fair value	16,995,000	31,385,000
Investment securities held to maturity	510,000	508,000
Securities held to maturity, gross unrealized gains	1,000	2,000
Securities held to maturity, gross unrealized losses	0	0
Securities held to maturity, at fair value	511,000	510,000
Collateralized Mortgage Backed Securities [Member]
Investment securities available for sale, amortized cost	93,124,000	128,820,000
Investment securities available for sale, gross unrealized gains	2,155,000	3,141,000
Investment securities available for sale, gross unrealized losses	163,000	277,000
Investment securities available for sale, at fair value	95,116,000	131,684,000
US States and Political Subdivisions Debt Securities [Member]
Investment securities available for sale, amortized cost	53,465,000	55,534,000
Investment securities available for sale, gross unrealized gains	536,000	1,305,000
Investment securities available for sale, gross unrealized losses	319,000	8,000
Investment securities available for sale, at fair value	53,682,000	56,831,000
Corporate Debt Securities [Member]
Investment securities available for sale, amortized cost	26,983,000	28,744,000
Investment securities available for sale, gross unrealized gains	60,000
Investment securities available for sale, gross unrealized losses	230,000	349,000
Investment securities available for sale, at fair value	$ 26,813,000	$ 28,395,000

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

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