Note 15 - Fair Values Measurements and Disclosures - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Securities available for sale	$ 26,045,675	$ 44,560,680
Fair Value, Measurements, Recurring [Member]
Securities available for sale	26,045,675	44,560,680
Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	26,045,675	44,560,680
Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	0	0
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	13,970,433	18,156,138
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	13,970,433	18,156,138
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	13,970,433	18,156,138
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	0	0
Residential Mortgage Backed Securities [Member]
Securities available for sale	12,075,242	26,404,542
Residential Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	12,075,242	26,404,542
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	0	0
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	12,075,242	26,404,542
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Securities available for sale	$ 0	$ 0