Note 11 - Fair Values - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Impaired loans	$ 8,757,000	$ 8,181,000
Foreclosed assets	396,000	811,000
Total	9,153,000	8,992,000
Fair Value, Inputs, Level 1 [Member]
Impaired loans	0	0
Foreclosed assets	0	0
Total	0	0
Fair Value, Inputs, Level 2 [Member]
Impaired loans	0	0
Foreclosed assets	0	0
Total	0	0
Fair Value, Inputs, Level 3 [Member]
Impaired loans	8,757,000	8,181,000
Foreclosed assets	396,000	811,000
Total	$ 9,153,000	$ 8,992,000