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Loan Quality and Allowance for Loan Losses - Troubled Debt Restructurings of Loans Receivable (Detail) $ in Thousands	3 Months Ended
	Sep. 30, 2019 USD ($) Loan	Sep. 30, 2018 USD ($) Loan
Financing Receivable Modifications [Line Items]
Number of loans | Loan	6	7
Pre-modification outstanding recorded investment	$ 2,859	$ 4,678
Post-modification outstanding recorded investment	2,848	4,676
Reserves included in and charge offs against the allowance for loan loss recognized at modification	$ 8	$ 2
Residential Mortgage [Member]
Financing Receivable Modifications [Line Items]
Number of loans | Loan	2	1
Pre-modification outstanding recorded investment	$ 1,002	$ 271
Post-modification outstanding recorded investment	$ 938	$ 270
Non-Residential Mortgage [Member]
Financing Receivable Modifications [Line Items]
Number of loans | Loan		1
Pre-modification outstanding recorded investment		$ 2,957
Post-modification outstanding recorded investment		2,955
Reserves included in and charge offs against the allowance for loan loss recognized at modification		$ 2
Commercial Business [Member]
Financing Receivable Modifications [Line Items]
Number of loans | Loan	3	5
Pre-modification outstanding recorded investment	$ 1,775	$ 1,450
Post-modification outstanding recorded investment	1,829	$ 1,451
Reserves included in and charge offs against the allowance for loan loss recognized at modification	$ 8
Home Equity Loans [Member]
Financing Receivable Modifications [Line Items]
Number of loans | Loan	1
Pre-modification outstanding recorded investment	$ 82
Post-modification outstanding recorded investment	$ 81

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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Reflects the amount of the write-down related to a troubled debt restructuring.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554

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