Note 5 - Investment Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Collateralized Mortgage Obligations [Member]
Amortized Cost	$ 150,708,000	$ 180,795,000
Investment securities available for sale, gross unrealized gains	2,292,000	523,000
Unrealized Losses	(134,000)	(3,173,000)
Fair Value	152,866,000	178,145,000
Total, held to ,maturity, amortized cost	164,150,000	146,458,000
Investment securities held to maturity, gross unrealized gains	3,602,000	402,000
Investment securities held to maturity, gross unrealized losses	(114,000)	(780,000)
Total, held to ,maturity, fair value	167,638,000	146,080,000
Collateralized Mortgage Backed Securities [Member]
Amortized Cost	9,357,000	10,073,000
Investment securities available for sale, gross unrealized gains	67,000	176,000
Unrealized Losses	(5,000)	(78,000)
Fair Value	9,419,000	10,171,000
Total, held to ,maturity, amortized cost	17,253,000	7,732,000
Investment securities held to maturity, gross unrealized gains	390,000
Investment securities held to maturity, gross unrealized losses		(21,000)
Total, held to ,maturity, fair value	17,643,000	7,711,000
US States and Political Subdivisions Debt Securities [Member]
Amortized Cost	24,141,000	22,814,000
Investment securities available for sale, gross unrealized gains	1,131,000	562,000
Unrealized Losses		(32,000)
Fair Value	25,272,000	23,344,000
Corporate Debt Securities [Member]
Amortized Cost	49,256,000	54,294,000
Investment securities available for sale, gross unrealized gains	52,000	135,000
Unrealized Losses	(1,509,000)	(300,000)
Fair Value	47,799,000	54,129,000
Asset-backed Securities [Member]
Amortized Cost	16,825,000	17,631,000
Investment securities available for sale, gross unrealized gains
Unrealized Losses	(762,000)	(626,000)
Fair Value	16,063,000	17,005,000
Collateralized Debt Obligations [Member]
Amortized Cost	3,065,000	3,070,000
Investment securities available for sale, gross unrealized gains
Unrealized Losses	(1,310,000)	(1,187,000)
Fair Value	1,755,000	1,883,000
Other Debt Obligations [Member]
Amortized Cost	115,000	115,000
Investment securities available for sale, gross unrealized gains		3,000
Unrealized Losses
Fair Value	115,000	118,000
Total, held to ,maturity, amortized cost	1,020,000	1,020,000
Investment securities held to maturity, gross unrealized gains
Investment securities held to maturity, gross unrealized losses
Total, held to ,maturity, fair value	1,020,000	1,020,000
US Government Agencies Debt Securities [Member]
Total, held to ,maturity, amortized cost	16,651,000	17,067,000
Investment securities held to maturity, gross unrealized gains	244,000	39,000
Investment securities held to maturity, gross unrealized losses	(10,000)	(72,000)
Total, held to ,maturity, fair value	16,885,000	17,034,000
Amortized Cost	253,467,000	288,792,000
Investment securities available for sale, gross unrealized gains	3,542,000	1,399,000
Unrealized Losses	(3,720,000)	(5,396,000)
Fair Value	253,289,000	284,795,000
Total, held to ,maturity, amortized cost	199,074,000	172,277,000
Investment securities held to maturity, gross unrealized gains	4,236,000	441,000
Investment securities held to maturity, gross unrealized losses	(124,000)	(873,000)
Total, held to ,maturity, fair value	$ 203,186,000	$ 171,845,000