Note 12 - Deposits - Composition of Deposits and Related Percentage Mix of Total Deposits (Details) - USD ($)	Mar. 31, 2017	Mar. 31, 2016
Savings, amount	$ 44,614,415	$ 33,010,962
Savings, percentage	11.00%	11.00%
Noninterest-bearing checking, amount	$ 30,401,454	$ 19,747,437
Noninterest-bearing checking, percentage	7.00%	6.00%
Interest-bearing checking, amount	$ 26,415,189	$ 13,298,677
Interest-bearing checking, percentage	6.00%	4.00%
Money market accounts, amount	$ 62,962,902	$ 52,576,567
Money market accounts, percentage	15.00%	17.00%
Time deposits, amount	$ 247,632,742	$ 195,031,411
Time deposits, percentage	60.00%	62.00%
Gross deposits, amount	$ 412,026,702	$ 313,665,054
Gross deposits, percentage	100.00%	100.00%
Premium on deposits asssumed	$ 829,072	$ 328,597
Total deposits, amount	$ 412,855,774	$ 313,993,651