Note 3 - Securities (Details) - Securities Held-to-maturity - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, amortized costs	$ 152,028	$ 161,452
Securities held-to-maturity, gross unrealized gains	6,513	7,225
Securities held-to-maturity, gross unrealized losses	509	974
Securities held-to-maturity, fair value	158,032	167,703
US Government Agencies Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, amortized costs	13,909	18,922
Securities held-to-maturity, gross unrealized gains	288	350
Securities held-to-maturity, gross unrealized losses	177	245
Securities held-to-maturity, fair value	14,020	19,027
US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, amortized costs	136,373	140,702
Securities held-to-maturity, gross unrealized gains	6,179	6,823
Securities held-to-maturity, gross unrealized losses	330	727
Securities held-to-maturity, fair value	142,222	146,798
Collateralized Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, amortized costs	327	415
Securities held-to-maturity, gross unrealized gains	36	51
Securities held-to-maturity, gross unrealized losses	0	0
Securities held-to-maturity, fair value	363	466
Corporate Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held-to-maturity, amortized costs	1,419	1,413
Securities held-to-maturity, gross unrealized gains	10	1
Securities held-to-maturity, gross unrealized losses	2	2
Securities held-to-maturity, fair value	$ 1,427	$ 1,412