Note 11 - Disclosures About Fair Value of Assets and Liabilities - Fair Value Quantitative Information (Details) - Fair Value, Inputs, Level 3 [Member] - Market Approach Valuation Technique [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Impaired Loans [Member]
Assets, fair value	$ 1,006,000	$ 5,000,000
Valuation technique	Market Comparable	Market Comparable
Unobservable input	Discount to reflect realizable value	Discount to reflect realizable value
Impaired Loans [Member] | Minimum [Member]
Range	0.00%	0.00%
Impaired Loans [Member] | Maximum [Member]
Range	100.00%	23.00%
Impaired Loans [Member] | Weighted Average [Member]
Range	7.00%	4.00%
Foreclosed Assets Held For Sale [Member]
Assets, fair value	$ 149
Valuation technique	Market Comparable	Market Comparable
Unobservable input	Discount to reflect realizable value	Discount to reflect realizable value
Range		0.00%
Foreclosed Assets Held For Sale [Member] | Minimum [Member]
Range
Foreclosed Assets Held For Sale [Member] | Maximum [Member]
Range	10.00%
Foreclosed Assets Held For Sale [Member] | Weighted Average [Member]
Range