Note 7 - Investment Securities (Details) - Investment Securities Available-for-sale - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	$ 362,568,000	$ 375,219,000
Investment securities available-for-sale, gross unrealized holding gains	4,635,000	5,073,000
Investment securities available-for-sale, gross unrealized holding losses	(2,727,000)	(3,698,000)
Investment securities available-for-sale, amortized cost	360,660,000	373,844,000
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	57,490,000	62,665,000
Investment securities available-for-sale, gross unrealized holding gains	308,000	212,000
Investment securities available-for-sale, gross unrealized holding losses	(44,000)	(472,000)
Investment securities available-for-sale, amortized cost	57,226,000	62,925,000
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	83,042,000	72,569,000
Investment securities available-for-sale, gross unrealized holding gains	1,493,000	1,500,000
Investment securities available-for-sale, gross unrealized holding losses	(85,000)	(150,000)
Investment securities available-for-sale, amortized cost	81,634,000	71,219,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	133,281,000	136,192,000
Investment securities available-for-sale, gross unrealized holding gains	1,793,000	1,819,000
Investment securities available-for-sale, gross unrealized holding losses	(203,000)	(466,000)
Investment securities available-for-sale, amortized cost	131,691,000	134,839,000
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	73,034,000	87,662,000
Investment securities available-for-sale, gross unrealized holding gains	494,000	330,000
Investment securities available-for-sale, gross unrealized holding losses	(599,000)	(1,300,000)
Investment securities available-for-sale, amortized cost	73,139,000	88,632,000
Collateralized Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	2,600,000	2,439,000
Investment securities available-for-sale, gross unrealized holding gains	215,000	160,000
Investment securities available-for-sale, gross unrealized holding losses	(1,024,000)	(1,240,000)
Investment securities available-for-sale, amortized cost	3,409,000	3,519,000
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	6,029,000	6,037,000
Investment securities available-for-sale, gross unrealized holding gains	23,000	30,000
Investment securities available-for-sale, gross unrealized holding losses	(11,000)
Investment securities available-for-sale, amortized cost	6,017,000	6,007,000
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	7,092,000	7,655,000
Investment securities available-for-sale, gross unrealized holding gains	309,000	1,022,000
Investment securities available-for-sale, gross unrealized holding losses	(761,000)	(70,000)
Investment securities available-for-sale, amortized cost	$ 7,544,000	$ 6,703,000