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Derivative Instruments and Hedging Activities - Additional Information (Detail) $ in Thousands | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 USD ($) Instrument | Sep. 30, 2018 USD ($) | Sep. 30, 2019 USD ($) Instrument | Jun. 30, 2019 USD ($)
Loan Origination Commitments [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Pipeline of loans held-for-sale | $ 65,900 |  | $ 65,900 | $ 46,200
Counter Party [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Financial collateral not included as offsetting amounts | 150 |  | 150 |
Interest Expense [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Estimated cash flow hedge gain (loss) to be reclassified in next twelve months |  |  | $ (1,200) |
Cash Flow Hedges [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Reclassifications to interest expense | $ 1,371 | $ 1,236 |  |
Cash Flow Hedges [Member] | Interest Rate Swaps [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Number of interest rate derivative instruments held | Instrument | 15 |  | 15 |
Derivative, notional amount | $ 1,000,000 |  | $ 1,000,000 |
Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Interest Expense [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Reclassifications to interest expense | $ 1,371 | $ 1,236 |  |

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- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994 + Details
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- Definition Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226006-175313 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=d3e41678-113959 + Details
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- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
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- Definition Number of interest rate derivative instruments held by the entity at the reporting date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959 + Details
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- Definition This is the principal amount outstanding for loans which are in the process of being securitized as of the date of the statement of financial position (across all types of loans). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118948506&loc=d3e107314-111719 + Details
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