Note 11 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Financial Instruments (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financial assets:
Cash and cash equivalents	$ 9,088,441	$ 18,774,419	$ 12,493,890	$ 12,303,200
Held-to-maturity securities	27,528	43,099
Federal Home Loan Bank stock	4,611,000	2,837,500
Mortgage loans held for sale	2,183,633	1,902,933
Loans, net	538,273,640	491,001,907
Interest receivable	1,947,063	1,986,692
Financial liabilities:
Deposits	505,362,750	517,385,695
FHLB and Federal Reserve advances	95,700,000	52,100,000
FHLB and Federal Reserve advances	95,764,840	53,227,960
Subordinated debentures	15,465,000	15,465,000
Interest payable	207,833	196,102
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and cash equivalents	9,088,441	18,774,419
Cash and cash equivalents	9,088,441	18,774,419
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Held-to-maturity securities	27,528	43,099
Held-to-maturity securities	28,153	43,935
Federal Home Loan Bank stock	4,611,000	2,837,500
Federal Home Loan Bank stock	4,611,000	2,837,500
Mortgage loans held for sale	2,183,633	1,902,933
Mortgage loans held for sale	2,183,633	1,902,933
Interest receivable	1,947,063	1,986,692
Financial liabilities:
Deposits	505,362,750	517,385,695
Deposits	504,829,161	511,225,380
Interest payable	207,833	196,102
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans, net	538,273,640	491,001,907
Loans, net	537,645,692	495,207,798
Financial liabilities:
Subordinated debentures	15,465,000	15,465,000
Subordinated debentures	$ 15,465,000	$ 15,465,000