Loans receivable (Details 7) - USD ($) $ in Thousands	Dec. 31, 2016	Jun. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	$ 10,135	$ 10,836
Loans Receivable, Recorded Investment, Loans Not Past Due	239,414	234,152
Loans Receivable, Recorded Investment, Total	249,549	244,988
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	5,606	4,530
Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	4,529	6,306
Residential Real Estate One To Four Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	9,436	10,089
Loans Receivable, Recorded Investment, Loans Not Past Due	182,229	176,036
Loans Receivable, Recorded Investment, Total	191,665	186,125
Residential Real Estate One To Four Family [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	5,477	4,377
Residential Real Estate One To Four Family [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	3,959	5,712
Residential Real Estate Multi Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans Receivable, Recorded Investment, Loans Not Past Due	16,033	15,559
Loans Receivable, Recorded Investment, Total	16,033	15,559
Residential Real Estate Multi Family [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Residential Real Estate Multi Family [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Residential Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	548
Loans Receivable, Recorded Investment, Loans Not Past Due	2,378	2,261
Loans Receivable, Recorded Investment, Total	2,378	2,809
Residential Real Estate Construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Residential Real Estate Construction [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	548
Land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans Receivable, Recorded Investment, Loans Not Past Due	1,327	1,186
Loans Receivable, Recorded Investment, Total	1,327	1,186
Land [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Land [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	548	0
Loans Receivable, Recorded Investment, Loans Not Past Due	1,407	1,735
Loans Receivable, Recorded Investment, Total	1,955	1,735
Farm [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Farm [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	548	0
Non residential real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	129	153
Loans Receivable, Recorded Investment, Loans Not Past Due	25,153	26,985
Loans Receivable, Recorded Investment, Total	25,282	27,138
Non residential real estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	129	153
Non residential real estate [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Commercial nonmortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans Receivable, Recorded Investment, Loans Not Past Due	2,308	1,847
Loans Receivable, Recorded Investment, Total	2,308	1,847
Commercial nonmortgage [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Commercial nonmortgage [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans on deposits [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans Receivable, Recorded Investment, Loans Not Past Due	1,741	1,813
Loans Receivable, Recorded Investment, Total	1,741	1,813
Loans on deposits [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans on deposits [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Home equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	17	37
Loans Receivable, Recorded Investment, Loans Not Past Due	6,425	6,118
Loans Receivable, Recorded Investment, Total	6,442	6,155
Home equity [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Home equity [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	17	37
Unsecured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	5	9
Loans Receivable, Recorded Investment, Loans Not Past Due	367	543
Loans Receivable, Recorded Investment, Total	372	552
Unsecured [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Unsecured [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	5	9
Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Loans Receivable, Recorded Investment, Loans Not Past Due	46	69
Loans Receivable, Recorded Investment, Total	46	69
Automobile [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	0	0
Automobile [Member] | Financing Receivables 30 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Recorded Investment, Total Past Due	$ 0	$ 0