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Fair Values of Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |  |
Available-for-sale Securities | $ 1,124,956 |  | $ 1,124,956 |  | $ 831,223
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 | 0 | $ 0 | 0 | $ 0 |
Impaired loans considered to be credit risk of non-collection | 250 |  | 250 |  |
Updated appraisal requirement floor | 250 |  | 250 |  |
Other real estate owned | 502 |  | 502 |  | 1,215
Financial instrument of credit risk | 100 |  | 100 |  | $ 100
Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Other Income, Assets and Liabilities Continue to be held |  | 0 |  | 0 |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 | 0 | 0 | 0 | 0 |
Total gains or losses included in earnings | 0 | 0 | 0 | 0 |
Derivatives mark to market | 218 | (160) | 1,371 | (2,122) |
Forward Contracts [Member] |  |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |  |
Derivatives mark to market | (400) |  | (1,300) |  |
Forward Contracts [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |  |
Derivatives mark to market | (265) | (102) | (666) | 132 |
Other Assets [Member] |  |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |  |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 | 0 | 0 | 0 | 0 |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 | 0 | 0 | 0 | 0 |
Total gains or losses included in earnings | $ 0 | $ 0 | $ 0 | $ 0 |
Minimum [Member] |  |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |  |
Swap Rates Term Used to Determine Yield Curve |  |  | 3 years |  |
Maximum [Member] |  |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |  |
Swap Rates Term Used to Determine Yield Curve |  |  | 30 years |  |

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