Loans receivable (Details 8) - USD ($) $ in Thousands	Dec. 31, 2016	Jun. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	$ 249,549	$ 244,988
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	55,963	57,411
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	6,930	7,321
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	12,497	12,488
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	174,159	167,768
Residential Real Estate One To Four Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	191,665	186,125
Residential Real Estate One To Four Family [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate One To Four Family [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	6,031	6,387
Residential Real Estate One To Four Family [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	11,475	11,970
Residential Real Estate One To Four Family [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate One To Four Family [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	174,159	167,768
Residential Real Estate Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	16,033	15,559
Residential Real Estate Multi Family [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	15,702	15,220
Residential Real Estate Multi Family [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate Multi Family [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	331	339
Residential Real Estate Multi Family [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate Multi Family [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	2,378	2,809
Residential Real Estate Construction [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	2,378	2,809
Residential Real Estate Construction [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate Construction [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate Construction [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Residential Real Estate Construction [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Non residential real estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	24,263	26,061
Non residential real estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	870	904
Non residential real estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	149	173
Non residential real estate [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Non residential real estate [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	1,327	1,186
Land [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	1,327	1,186
Land [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Land [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Land [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Land [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	1,955	1,735
Farm [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	1,418	1,735
Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	537	0
Farm [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Farm [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Loans on deposits [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	1,741	1,813
Loans on deposits [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	1,741	1,813
Loans on deposits [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Loans on deposits [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Loans on deposits [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Loans on deposits [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Home equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	6,442	6,155
Home equity [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	6,442	6,149
Home equity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Home equity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	6
Home equity [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Home equity [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Unsecured [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	372	552
Unsecured [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	338	552
Unsecured [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	29	0
Unsecured [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	5	0
Unsecured [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Unsecured [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Commercial Non-mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	2,308	1,817
Commercial Non-mortgage [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	30
Commercial Non-mortgage [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Commercial Non-mortgage [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Commercial Non-mortgage [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	46	69
Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	46	69
Automobile [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Automobile [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Automobile [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	0	0
Automobile [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Recorded Investment	$ 0	$ 0