Note 6 - Investment Securities (Details) - The Amortized Cost and Estimated Fair Value of the Securities Portfolio by Contractual Maturity - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
The Amortized Cost and Estimated Fair Value of the Securities Portfolio by Contractual Maturity [Abstract]
Due in one year or less	$ 12,034
Due in one year or less	12,062
Due in one year or less	0
Due in one year or less	0
Due after one year through five years	156,768
Due after one year through five years	157,760
Due after one year through five years	0
Due after one year through five years	0
Due after five years through ten years	92,094
Due after five years through ten years	92,396
Due after five years through ten years	705
Due after five years through ten years	799
Due after ten years	14,270
Due after ten years	13,800
Due after ten years	2,998
Due after ten years	3,072
Mortgage-backed securities	336,194
Mortgage-backed securities	341,427
Mortgage-backed securities	0
Mortgage-backed securities	0
Total	611,360
Total	617,445
Total	3,703	$ 3,728
Total	$ 3,871	$ 3,923