Note 5 - Securities (Details) - Securities Held-to-maturity - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Held to Maturity:
Securities held-to-maturity, amortized costs	$ 155,704	$ 161,452
Securities held-to-maturity, gross unrealized gains	5,488	7,225
Securities held-to-maturity, gross unrealized losses	2,267	974
Securities held-to-maturity, fair value	158,925	167,703
US Government Agencies Debt Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	15,914	18,922
Securities held-to-maturity, gross unrealized gains	302	350
Securities held-to-maturity, gross unrealized losses	428	245
Securities held-to-maturity, fair value	15,788	19,027
US States and Political Subdivisions Debt Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	138,001	140,702
Securities held-to-maturity, gross unrealized gains	5,133	6,823
Securities held-to-maturity, gross unrealized losses	1,838	727
Securities held-to-maturity, fair value	141,296	146,798
Collateralized Mortgage Backed Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	373	415
Securities held-to-maturity, gross unrealized gains	47	51
Securities held-to-maturity, fair value	420	466
Corporate Debt Securities [Member]
Held to Maturity:
Securities held-to-maturity, amortized costs	1,416	1,413
Securities held-to-maturity, gross unrealized gains	6	1
Securities held-to-maturity, gross unrealized losses	1	2
Securities held-to-maturity, fair value	$ 1,421	$ 1,412