Note 15 - Fair Values Measurements and Disclosures - Assets Measured at Fair Value on a Non-recurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Foreclosed assets	$ 84,100	$ 35,500
Impaired loans, net	510,682	3,025,398
Fair Value, Inputs, Level 1 [Member]
Foreclosed assets	0	0
Impaired loans, net	0	0
Fair Value, Inputs, Level 2 [Member]
Foreclosed assets	0	0
Impaired loans, net	0	0
Fair Value, Inputs, Level 3 [Member]
Foreclosed assets	84,100	35,500
Impaired loans, net	$ 510,682	$ 3,025,398