Allowance for Losses on Loans - Narrative (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Sep. 30, 2025 |
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| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||
| Provision for credit losses | $ 11,000 | $ 2,000 | $ 18,500 | $ 4,750 | |
| Allowance for credit loss, charge-off (recovery) | 1,619 | $ 5,441 | 5,889 | $ 10,735 | |
| Gross loans | $ 20,232,707 | $ 20,232,707 | $ 20,288,338 | ||
| Non-accrual percent of total loans | 0.63% | 0.63% | 0.63% | ||
| Delinquency percent, past due | 0.75% | 0.75% | 0.60% | ||
| Financial Asset Originated | |||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||
| Non-accrual loans | $ 127,569 | $ 127,569 | $ 128,628 | ||
| Non-Performing Loans | |||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||||
| Gross loans | $ 135,748 | $ 135,748 | $ 143,022 | ||
| Ratio of non-performing assets to total assets | 0.50% | 0.50% | 0.50% | ||
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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. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount, excluding accrued interest, of decrease (increase) in allowance for credit loss on financing receivable from writeoff (recovery). Excludes net investment in lease. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Percentage of financing receivable balance that is past due. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Financing Receivable, Nonaccrual, Percent of Total Loans No definition available.
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- Definition Ratio of Non-Performing Assets to Total Assets No definition available.
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