Note 11 - Fair Value Measurement and Disclosure - Quantitative Information About Assets Measured at Fair Value (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Market Approach Valuation Technique [Member] | Foreclosed Assets [Member] | Minimum [Member]
Appraisal adjustments	23.00%	6.70%
Market Approach Valuation Technique [Member] | Foreclosed Assets [Member] | Maximum [Member]
Appraisal adjustments	50.00%	63.60%
Market Approach Valuation Technique [Member] | Foreclosed Assets [Member]
Assets, fair value disclosure, noncrecurring	$ 74,753	$ 330,245
Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Minimum [Member]
Appraisal adjustments	29.90%	10.00%
Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Maximum [Member]
Appraisal adjustments	74.50%	70.00%
Market Approach Valuation Technique [Member] | Impaired Loans [Member]
Assets, fair value disclosure, noncrecurring	$ 2,271,952	$ 2,170,027
Income Approach Valuation Technique [Member] | Impaired Loans [Member]
Assets, fair value disclosure, noncrecurring	$ 312,631	$ 107,891
Discount Rate	10.00%	10.00%