Loans Receivable - Reconciliation of Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	$ 1,713	$ 2,422
Current	624,272	491,459
Total loans	625,985	493,881
Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total loans	600,000	471,500
Residential segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	1,262	2,071
Current	564,867	432,461
Total loans	566,129	434,532
Residential segment | Commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
Current	161,182	125,623
Total loans	161,182	125,623
Residential segment | Construction and land
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	46	137
Current	50,305	18,990
Total loans	50,351	19,127
Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	451	351
Current	42,481	44,234
Total loans	42,932	44,585
Consumer | Home equity
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	346	194
Current	33,563	36,193
Total loans	33,909	36,387
Consumer | Other consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	105	157
Current	8,918	8,041
Total loans	9,023	8,198
Commercial business loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
Current	16,924	14,764
Total loans	16,924	14,764
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	1,111	139
30 to 59 Days Past Due | Residential segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	662	0
30 to 59 Days Past Due | Residential segment | Commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
30 to 59 Days Past Due | Residential segment | Construction and land
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
30 to 59 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	449	139
30 to 59 Days Past Due | Consumer | Home equity
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	344	81
30 to 59 Days Past Due | Consumer | Other consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	105	58
30 to 59 Days Past Due | Commercial business loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	88	1,448
60 to 89 Days Past Due | Residential segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	88	1,344
60 to 89 Days Past Due | Residential segment | Commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
60 to 89 Days Past Due | Residential segment | Construction and land
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	114
60 to 89 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	104
60 to 89 Days Past Due | Consumer | Home equity
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	15
60 to 89 Days Past Due | Consumer | Other consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	89
60 to 89 Days Past Due | Commercial business loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
90 Days or More Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	514	835
90 Days or More Past Due | Residential segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	512	727
90 Days or More Past Due | Residential segment | Commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
90 Days or More Past Due | Residential segment | Construction and land
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	46	23
90 Days or More Past Due | Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	2	108
90 Days or More Past Due | Consumer | Home equity
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	2	98
90 Days or More Past Due | Consumer | Other consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	10
90 Days or More Past Due | Commercial business loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
One- to four-family | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	1,216	1,934
Current	307,255	254,762
Total loans	308,471	256,696
One- to four-family | 30 to 59 Days Past Due | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	662	0
One- to four-family | 60 to 89 Days Past Due | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	88	1,230
One- to four-family | 90 Days or More Past Due | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	466	704
Multifamily | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
Current	46,125	33,086
Total loans	46,125	33,086
Multifamily | 30 to 59 Days Past Due | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
Multifamily | 60 to 89 Days Past Due | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	0	0
Multifamily | 90 Days or More Past Due | Residential segment | Real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Past due loans	$ 0	$ 0