Note 7 - Loans Receivable and Allowance for Loan Losses - Outstanding Commitments and Unused Lines of Credit (Details) - USD ($)	Mar. 31, 2017	Mar. 31, 2016
Unused commercial lines of credit [Member]
Outstanding commitments and unused lines of credit	$ 10,733,345	$ 9,845,571
Unused home equity lines of credit [Member]
Outstanding commitments and unused lines of credit	22,993,289	16,004,725
Unused consumer lines of credit [Member]
Outstanding commitments and unused lines of credit	1,110,155	29,656
Residential construction loan commitments [Member]
Outstanding commitments and unused lines of credit	8,047,156	8,166,473
Commercial construction loan commitments [Member]
Outstanding commitments and unused lines of credit	7,091,564	1,384,932
Home equity loan commitments [Member]
Outstanding commitments and unused lines of credit	84,000	536,000
Commercial loan commitments [Member]
Outstanding commitments and unused lines of credit	1,089,218	411,500
Standby letters of credit [Member]
Outstanding commitments and unused lines of credit	$ 472,354	$ 273,981