Note 5 - Securities (Details) - Securities Held-to-maturity - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Held to Maturity:
Securities held-to-maturity, amortized costs	$ 154,644	$ 161,452
Securities held-to-maturity, gross unrealized gains	6,036	7,225
Securities held-to-maturity, gross unrealized losses	1,237	974
Securities held-to-maturity, fair value	159,443	167,703
US Government Agencies Debt Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	14,912	18,922
Securities held-to-maturity, gross unrealized gains	343	350
Securities held-to-maturity, gross unrealized losses	216	245
Securities held-to-maturity, fair value	15,039	19,027
US States and Political Subdivisions Debt Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	137,969	140,702
Securities held-to-maturity, gross unrealized gains	5,635	6,823
Securities held-to-maturity, gross unrealized losses	1,020	727
Securities held-to-maturity, fair value	142,584	146,798
Collateralized Mortgage Backed Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	346	415
Securities held-to-maturity, gross unrealized gains	40	51
Securities held-to-maturity, fair value	386	466
Corporate Debt Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	1,417	1,413
Securities held-to-maturity, gross unrealized gains	18	1
Securities held-to-maturity, gross unrealized losses	1	2
Securities held-to-maturity, fair value	$ 1,434	$ 1,412