Note 11 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Assets Measured on Recurring Basis (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale securities	$ 92,399,235	$ 97,292,487
Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities		99,000
Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities	92,399,000	97,193,000
Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities	38,337,525	31,349,162
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities	38,338,000	31,349,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
Equity Securities [Member]
Available-for-sale securities		99,517
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities		99,000
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
Corporate Debt Securities [Member]
Available-for-sale securities	7,053,522	3,813,700
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities	7,053,000	3,814,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
US Government Agencies Debt Securities [Member]
Available-for-sale securities		8,396,784
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities		8,397,000
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale securities	47,008,188	53,633,324
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities	47,008,000	53,633,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities