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Fair Value Measurements Fair Value Measurement, Measured On Non-Recurring Basis, Signfiicant Unobservable Inputs, Quantitative Information (Details) - Fair Value, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands | Sep. 30, 2019 | Sep. 30, 2018
--- | --- | ---
Impaired Loans [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Assets, Fair Value Disclosure | $ 9,810 | $ 24,428
Real estate and other repossessed assets [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Assets, Fair Value Disclosure | 936 | 6,545
Discounted Cash Flow [Member] | Impaired Loans [Member] | Management knowledge of Industry [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Assets, Fair Value Disclosure | 9,810 | 24,428
Discounted Cash Flow [Member] | Real estate and other repossessed assets [Member] | Marketability adjustments off appraised value |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Assets, Fair Value Disclosure | $ 936 |
Discounted Cash Flow [Member] | Real estate and other repossessed assets [Member] | Recoverable oil and gas reserves, forward-looking commodity prices, and estimated operating costs [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Assets, Fair Value Disclosure |  | $ 6,545
Minimum [Member] | Impaired Loans [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance | 8.00% | 41.00%
Minimum [Member] | Real estate and other repossessed assets [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair Value Measurement, Percentage of Appraised Value. Minimum | 75.00% |
Maximum [Member] | Impaired Loans [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance | 76.00% | 84.00%
Maximum [Member] | Real estate and other repossessed assets [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair Value Measurement, Percentage of Appraised Value. Minimum | 89.00% |
Weighted Average [Member] | Impaired Loans [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance | 28.00% | 55.00%
Weighted Average [Member] | Real estate and other repossessed assets [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair Value Measurement, Percentage of Appraised Value. Minimum | 85.00% |

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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