Note 5 - Investment Securities Available-for-sale (Details) - Investment Securities Pledged as Collateral - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investment securities available for sale pledged	$ 121,824	$ 133,195
Municpal and Other Secured Deposit [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investment securities available for sale pledged	84,732	84,255
Retail Purchase Agreements [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investment securities available for sale pledged	24,873	36,629
Federal Reserve Line of Credit [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investment securities available for sale pledged	1,313	1,352
Correspondent Banks Line of Credit [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Investment securities available for sale pledged	$ 10,906	$ 10,959