Note 4 - Investment Securities (Details) - Investment Securities - Unrealized Loss (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Note 4 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	$ 32,987	$ 100,035
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	70	958
Securities in a continuous unrealized loss position, 12 months or more, fair value	8,883	7,891
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	113	136
Securities in a continuous unrealized loss position, fair value	41,870	107,926
Securities in a continuous unrealized loss position, unrealized losses	183	1,094
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Note 4 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	17,427	61,106
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	20	527
Securities in a continuous unrealized loss position, 12 months or more, fair value	2,975	3,093
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	21	20
Securities in a continuous unrealized loss position, fair value	20,402	64,109
Securities in a continuous unrealized loss position, unrealized losses	41	547
Municipal Securities [Member]
Note 4 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	4,253	5,469
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	21	99
Securities in a continuous unrealized loss position, 12 months or more, fair value		904
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses		10
Securities in a continuous unrealized loss position, fair value	4,253	6,373
Securities in a continuous unrealized loss position, unrealized losses	21	109
Corporate Bonds [Member]
Note 4 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value	11,307	21,670
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses	29	256
Securities in a continuous unrealized loss position, 12 months or more, fair value	5,908	3,894
Securities in a continuous unrealized loss position, 12 months or more, unrealized losses	92	106
Securities in a continuous unrealized loss position, fair value	17,215	25,564
Securities in a continuous unrealized loss position, unrealized losses	121	362
US Government Agencies Debt Securities [Member]
Note 4 - Investment Securities (Details) - Investment Securities - Unrealized Loss [Line Items]
Securities in a continuous unrealized loss position, less than 12 months, fair value		11,790
Securities in a continuous unrealized loss position, less than 12 months, unrealized losses		76
Securities in a continuous unrealized loss position, fair value		11,790
Securities in a continuous unrealized loss position, unrealized losses		$ 76