Note 8 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Assets Measured on Recurring Basis (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities	$ 94,000	$ 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
Equity Securities [Member]
Available-for-sale securities	93,919	99,517
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	40,238,000	31,349,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities	40,237,710	31,349,162
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
US Government Agencies Debt Securities [Member]
Available-for-sale securities		8,396,784
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	5,967,000	3,814,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
Corporate Debt Securities [Member]
Available-for-sale securities	5,967,225	3,813,700
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	50,274,000	53,633,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [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	50,274,192	53,633,324
Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities	94,000	99,000
Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities	96,479,000	97,193,000
Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities
Available-for-sale securities	$ 96,573,046	$ 97,292,487