Note 8 - Derivative - Interest Rate Swap Agreement - Cash Flow Derivative Gains (Loss) Recorded In AOCI and the Statement of Income (Details) - Interest Rate Swap [Member] - Cash Flow Hedging [Member]	6 Months Ended
	Sep. 30, 2017 USD ($)
Amount of gain (loss) recognized in OCI (effective portion)	$ (183,238)
Amount of gain (loss) reclassified from OCI to Interest Income
Amount of gain (loss) recognized in Other Noninterest Income (ineffective portion)	$ (3,679)