Note 8 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Financial Instruments (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and cash equivalents	$ 9,798,780	$ 18,774,419
Cash and cash equivalents	9,798,780	18,774,419
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Held-to-maturity securities	33,858	43,099
Held-to-maturity securities	34,702	43,935
Federal Home Loan Bank stock	3,919,000	2,837,500
Federal Home Loan Bank stock	3,919,000	2,837,500
Mortgage loans held for sale	1,977,683	1,902,933
Mortgage loans held for sale	1,977,683	1,902,933
Interest receivable	1,880,601	1,986,692
Financial liabilities:
Deposits	514,414,560	517,385,695
Deposits	504,216,146	511,225,380
Federal Home Loan Bank advances	78,400,000	52,100,000
Federal Home Loan Bank advances	78,821,920	53,227,960
Interest payable	198,173	196,102
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans, net	518,948,805	491,001,907
Loans, net	517,815,050	495,207,798
Financial liabilities:
Subordinated debentures	15,465,000	15,465,000
Subordinated debentures	15,465,000	15,465,000
Cash and cash equivalents	9,798,780	18,774,419	$ 21,417,331	$ 12,493,890
Held-to-maturity securities	33,858	43,099
Federal Home Loan Bank stock	3,919,000	2,837,500
Mortgage loans held for sale	1,977,683	1,902,933
Loans, net	518,948,805	491,001,907
Deposits	514,414,560	517,385,695
Subordinated debentures	15,465,000	15,465,000
Interest payable	$ 198,173	$ 196,102