Note 2 - Investment Securities (Details) - Investment Securities - Unrealized Loss - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Note 2 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	$ 73,386	$ 100,035
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	404	958
Securities in a continuous unrealized loss position, 12 months or more, fair value	13,921	7,891
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	236	136
Securities in a continuous unrealized loss position, fair value	87,307	107,926
Securities in a continuous unrealized loss position, unrealized losses	640	1,094
US Government Agencies Debt Securities [Member]
Note 2 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	3,785	11,790
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	12	76
Securities in a continuous unrealized loss position, 12 months or more, fair value	0	0
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	0	0
Securities in a continuous unrealized loss position, fair value	3,785	11,790
Securities in a continuous unrealized loss position, unrealized losses	12	76
Collateralized Mortgage Backed Securities [Member]
Note 2 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	51,956	61,106
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	264	527
Securities in a continuous unrealized loss position, 12 months or more, fair value	2,641	3,093
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	7	20
Securities in a continuous unrealized loss position, fair value	54,597	64,199
Securities in a continuous unrealized loss position, unrealized losses	271	547
US States and Political Subdivisions Debt Securities [Member]
Note 2 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	1,530	5,469
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	8	99
Securities in a continuous unrealized loss position, 12 months or more, fair value	0	904
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	0	10
Securities in a continuous unrealized loss position, fair value	1,530	6,373
Securities in a continuous unrealized loss position, unrealized losses	8	109
Corporate Debt Securities [Member]
Note 2 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	16,115	21,670
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	120	256
Securities in a continuous unrealized loss position, 12 months or more, fair value	11,280	3,894
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	229	106
Securities in a continuous unrealized loss position, fair value	27,395	25,564
Securities in a continuous unrealized loss position, unrealized losses	$ 349	$ 362