Loans Receivable - Summary of Loans Individually Evaluated for Impairment (Excluding Loans Acquired with Deteriorated Credit Quality) by Class of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable Impaired [Line Items]
Impaired loans, unpaid principal balance	$ 10,455	$ 22,440
Impaired loans, recorded investment	9,114	17,322
Allowance for loan losses	451	1,142
Residential [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, unpaid principal balance	1,659	4,216
Impaired loans with no related allowance recorded, recorded investment	1,576	4,014
Impaired loans with an allowance recorded, unpaid principal balance	742	395
Impaired loans with an allowance recorded, recorded investment	784	457
Impaired loans, recorded investment	2,360	4,471
Allowance for loan losses	154	131
Commercial [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, unpaid principal balance	1,765	2,935
Impaired loans with no related allowance recorded, recorded investment	1,683	2,411
Impaired loans, recorded investment	1,683	2,411
Commercial Loans [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, unpaid principal balance	2,254	9,433
Impaired loans with no related allowance recorded, recorded investment	2,098	4,979
Impaired loans with an allowance recorded, unpaid principal balance	353	1,190
Impaired loans with an allowance recorded, recorded investment	353	1,190
Impaired loans, recorded investment	2,451	6,169
Allowance for loan losses	9	9
Home Equity Lines Of Credit [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, unpaid principal balance	341	599
Impaired loans with no related allowance recorded, recorded investment	341	599
Impaired loans with an allowance recorded, unpaid principal balance	84	11
Impaired loans with an allowance recorded, recorded investment	19	11
Impaired loans, recorded investment	360	610
Allowance for loan losses	12	5
Construction [Member]
Financing Receivable Impaired [Line Items]
Impaired loans with no related allowance recorded, unpaid principal balance		404
Impaired loans with no related allowance recorded, recorded investment		404
Impaired loans with an allowance recorded, unpaid principal balance	3,257	3,257
Impaired loans with an allowance recorded, recorded investment	2,260	3,257
Impaired loans, recorded investment	2,260	3,661
Allowance for loan losses	$ 276	$ 997

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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