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Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Thousands | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018
Commitment and Contingencies [Line Items] |  |  |  |  |  |
Weighted average remaining lease term | 8 years 10 months 24 days |  |  |  |  |
Weighted average discount rate | 2.00% |  |  |  |  |
Operating lease payments | $ 3,178 |  |  |  |  |
Right-of-use assets obtained in exchange for lease liabilities | 2,734 |  |  |  |  |
Loans in process | 1,289,812 |  | $ 1,201,341 |  |  |
Allowance for loan losses | 139,501 | $ 132,513 | 131,534 | $ 133,086 | $ 131,165 | $ 129,257
Unfunded Loan Commitment |  |  |  |  |  |
Commitment and Contingencies [Line Items] |  |  |  |  |  |
Allowance for loan losses | 8,500 |  | 6,900 |  |  |
Loans and Leases Receivable |  |  |  |  |  |
Commitment and Contingencies [Line Items] |  |  |  |  |  |
Loans in process | $ 2,646,603 |  | $ 2,379,089 |  |  |

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- Definition Amount of undisbursed portion of the loan receivable balance (loans in process). Excludes loans and leases covered under loss sharing agreements. + References No definition available. + Details
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- Definition Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918643-209977 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (g)(1) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980 + Details
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- Definition Weighted average discount rate for operating lease calculated at point in time. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (g)(4) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 55 -Paragraph 53 -URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971 + Details
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- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 55 -Paragraph 53 -URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (g)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980 + Details
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