Note 4 - Financial Instruments With Off-balance-sheet Risk - Contract Amounts (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Financial instruments with off-balance-sheet risk	$ 96,036,122	$ 77,873,584
Commitments to Originate and Sell Mortgage Loans [Member]
Financial instruments with off-balance-sheet risk	35,428,610	34,268,309
Commitments to Extend Credit [Member]
Financial instruments with off-balance-sheet risk	41,375,723	25,323,822
Unused lines of Credit [Member]
Financial instruments with off-balance-sheet risk	19,231,789	18,281,453
Standby Letters of Credit 1 [Member]
Financial instruments with off-balance-sheet risk