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Disclosures about Fair Value of Assets and Liabilities - Quantitative Information about Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements (Detail) $ in Thousands | 3 Months Ended |
--- | --- | ---
Jun. 30, 2019 USD ($) | Dec. 31, 2019 USD ($)
Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights | $ 853 | $ 888
Marketability Discount [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Impaired loans (collateral-dependent) | $ 33 |
Impaired loans (collateral-dependent) | 0.111 |
Comparability Adjustments [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Foreclosed assets | $ 512 |
Minimum [Member] | Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.095 | 0.095
Minimum [Member] | Constant Prepayment Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.083 | 0.088
Minimum [Member] | Probability of Default [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.0005 | 0.0005
Maximum [Member] | Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.115 | 0.115
Maximum [Member] | Constant Prepayment Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.110 | 0.111
Maximum [Member] | Probability of Default [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.0012 | 0.0012
Maximum [Member] | Comparability Adjustments [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Foreclosed assets | 0.078 |
Weighted Average [Member] | Discount Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.095 | 0.095
Weighted Average [Member] | Constant Prepayment Rate [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.090 | 0.097
Weighted Average [Member] | Probability of Default [Member] | Discounted Cash Flow [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Mortgage servicing rights, measurement input | 0.0011 | 0.0011
Weighted Average [Member] | Marketability Discount [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Impaired loans (collateral-dependent) | 0.111 |
Weighted Average [Member] | Comparability Adjustments [Member] | Market Comparable Properties [Member] |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Foreclosed assets | 0.078 |

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