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Loan Quality and Allowance for Loan Losses - Troubled Debt Restructurings of Loans Receivable (Detail) $ in Thousands | 3 Months Ended
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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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- Definition 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 + Details
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- Definition 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 + Details
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- Definition 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 + Details
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- Definition Reflects the amount of the write-down related to a troubled debt restructuring. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
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