Note 5 - Loans Receivable and Allowance for Loan Losses - Number of Contracts and Outstanding Loan Balance at Time of Modification (Details)	3 Months Ended
Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Financing Receivable, Modifications, Number of Contracts	0	0
Real Estate Loans [Member] \| One to four family, Residential [Member]
Financing Receivable, Modifications, Number of Contracts	1	1
Outstanding recorded investment	$ 20,866	$ 1,931

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

Name:	us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration