Note 11 - Quantitative Information for Financial Instruments Measured at Fair Value (Details) - Fair Value, Inputs, Level 3 [Member] - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Comparability Adjustments	(31.77%)	(31.77%)
Fair Value Inputs, Management Adjustments	0.00%	0.00%
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Comparability Adjustments	34.00%	34.00%
Fair Value Inputs, Management Adjustments	10.00%	10.00%
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Comparability Adjustments	1.12%	1.12%
Fair Value Inputs, Management Adjustments	5.00%	5.00%
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member]
Assets measured at fair value	$ 24	$ 28
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Cap Rate	11.00%	11.00%
Real Estate Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Comparability Adjustments	(31.77%)	(31.77%)
Fair Value Inputs, Management Adjustments	0.00%	0.00%
Real Estate Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Comparability Adjustments	34.00%	34.00%
Fair Value Inputs, Management Adjustments	90.00%	10.00%
Real Estate Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Comparability Adjustments	1.12%	1.12%
Fair Value Inputs, Management Adjustments	45.00%	5.00%
Real Estate Portfolio Segment [Member] | Commercial [Member] | Market Approach Valuation Technique [Member]
Assets measured at fair value	$ 5,325	$ 7,348
Real Estate Portfolio Segment [Member] | Commercial [Member] | Income Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Cap Rate	10.33%	10.25%
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Comparability Adjustments	(5.00%)	(5.00%)
Fair Value Inputs, Management Adjustments	0.00%	0.00%
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Comparability Adjustments	99.00%	99.00%
Fair Value Inputs, Management Adjustments	10.00%	10.00%
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Comparability Adjustments	47.00%	47.00%
Fair Value Inputs, Management Adjustments	5.00%	5.00%
Real Estate Portfolio Segment [Member] | Commercial Construction [Member] | Market Approach Valuation Technique [Member]
Assets measured at fair value	$ 51	$ 51
Real Estate Portfolio Segment [Member] | Residential [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Comparability Adjustments	(22.00%)	(22.00%)
Fair Value Inputs, Management Adjustments	0.00%	0.00%
Real Estate Portfolio Segment [Member] | Residential [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Comparability Adjustments	0.00%	10.80%
Fair Value Inputs, Management Adjustments	40.00%	25.00%
Real Estate Portfolio Segment [Member] | Residential [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Comparability Adjustments	(11.00%)	5.60%
Fair Value Inputs, Management Adjustments	20.00%	12.50%
Real Estate Portfolio Segment [Member] | Residential [Member] | Market Approach Valuation Technique [Member]
Assets measured at fair value	$ 436	$ 767
Real Estate Portfolio Segment [Member] | Farmland [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Comparability Adjustments	(27.00%)	(27.00%)
Fair Value Inputs, Management Adjustments	10.00%	10.00%
Real Estate Portfolio Segment [Member] | Farmland [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs, Comparability Adjustments	15.00%	15.00%
Fair Value Inputs, Management Adjustments	75.00%	75.00%
Real Estate Portfolio Segment [Member] | Farmland [Member] | Market Approach Valuation Technique [Member] | Weighted Average [Member]
Fair Value Inputs, Comparability Adjustments	(6.00%)	(6.00%)
Fair Value Inputs, Management Adjustments	42.50%	42.50%
Real Estate Portfolio Segment [Member] | Farmland [Member] | Market Approach Valuation Technique [Member]
Assets measured at fair value	$ 351	$ 351
Market Approach Valuation Technique [Member] | Minimum [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Comparability Adjustments	(50.80%)	(50.80%)
Fair Value Inputs, Management Adjustments	0.62%	15.53%
Market Approach Valuation Technique [Member] | Maximum [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Comparability Adjustments	142.90%	142.90%
Fair Value Inputs, Management Adjustments	72.75%	72.75%
Market Approach Valuation Technique [Member] | Weighted Average [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Comparability Adjustments	46.05%	46.05%
Fair Value Inputs, Management Adjustments	29.23%	43.37%
Market Approach Valuation Technique [Member] | Other Real Estate Owned [Member]
Assets measured at fair value	$ 2,941	$ 2,536
Income Approach Valuation Technique [Member] | Weighted Average [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Discount Rate	12.50%	12.50%