Note 8 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Foreclosed Real Estate [Member] | Fair Value, Inputs, Level 3 [Member] | Minimum [Member]
Fair Value Inputs, Estimated Selling Costs	1.00%		9.00%
Foreclosed Real Estate [Member] | Fair Value, Inputs, Level 3 [Member] | Maximum [Member]
Fair Value Inputs, Estimated Selling Costs	46.00%		43.00%
Foreclosed Real Estate [Member] | Fair Value, Inputs, Level 3 [Member] | Weighted Average [Member]
Fair Value Inputs, Estimated Selling Costs	38.00%		30.00%
Foreclosed Real Estate [Member]
SEC Schedule III, Real Estate, Write-down or Reserve, Amount	$ 83,000	$ 0
Impaired Loan [Member] | Fair Value, Inputs, Level 3 [Member] | Minimum [Member]
Fair Value Inputs, Estimated Selling Costs	10.00%		10.00%
Impaired Loan [Member] | Fair Value, Inputs, Level 3 [Member] | Maximum [Member]
Fair Value Inputs, Estimated Selling Costs	63.00%		59.00%
Impaired Loan [Member] | Fair Value, Inputs, Level 3 [Member] | Weighted Average [Member]
Fair Value Inputs, Estimated Selling Costs	23.00%		16.00%
Impaired Loan [Member]
Provision for Loan and Lease Losses	$ 106,000	35,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		$ 0
Provision for Loan and Lease Losses	$ 75,000	$ 0