Loans Receivable - Additional Information (Detail)	12 Months Ended
Jun. 30, 2018 USD ($) Loan	Jun. 30, 2017 USD ($) Loan	Jun. 30, 2016 USD ($) Loan
Loans and Leases Receivable Disclosure [Line Items]
Acquired loans accounted for as purchased credit impaired loans	$ 1,800,000	$ 2,700,000
Number of loans classified as troubled debt restructurings \| Loan	12	20
Value of loans classified as troubled debt restructurings	$ 3,800,000	$ 9,900,000
Specific reserves	$ 139,000	$ 145,000
Troubled debt restructurings for which there was a payment default \| Loan		2
Commercial Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Troubled debt restructurings for which there was a payment default \| Loan	2
Increase allowance for loan loss	$ 2,000
Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Troubled debt restructurings for which there was a payment default \| Loan		1	1
Increase allowance for loan loss		$ 0	$ 0
Home Equity Lines Of Credit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Troubled debt restructurings for which there was a payment default \| Loan		1
Increase allowance for loan loss		$ 0

Financing receivable modifications number of contracts outstanding.

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- Definition

Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings.

+ References

No definition available.

+ Details

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- Definition

Amount of increase (decrease) of allowance reserve for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

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- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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