Note 15 - Fair Values Measurements and Disclosures - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Securities available for sale	$ 24,515,759	$ 25,533,767
Fair Value, Recurring [Member]
Securities available for sale	24,515,759	25,533,767
Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Securities available for sale	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Securities available for sale	24,515,759	25,533,767
Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Securities available for sale	0	0
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	13,465,317	13,186,788
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Securities available for sale	13,465,317	13,186,788
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Securities available for sale	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Securities available for sale	13,465,317	13,186,788
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Securities available for sale	0	0
Residential Mortgage Backed Securities [Member]
Securities available for sale	11,050,442	12,346,979
Residential Mortgage Backed Securities [Member] | Fair Value, Recurring [Member]
Securities available for sale	11,050,442	12,346,979
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Securities available for sale	0	0
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Securities available for sale	11,050,442	12,346,979
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Securities available for sale	$ 0	$ 0