Note 6 - Loans Receivable and Allowance for Loan Losses - Number of Contracts and Outstanding Loan Balance at Time of Modification (Details)	3 Months Ended	6 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Number of contracts	0	0
Real Estate Loans [Member] \| One-to four-family [Member]
Number of contracts			1	11
Outstanding recorded investment			$ 1,931	$ 712,786

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration