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v3.20.2

Loans and Allowance for Credit Losses - Additional Information (Detail) | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($) | Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($) | Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Non Accrual Status Of Loans After Number Of Days Past Due |  |  | 90 days |  |
Default Status Of TDRs After Number Of Days Past Due |  |  | 90 days |  |
Unfunded commitments related to nonperforming loans | $ 1,100,000 |  | $ 1,100,000 |  | $ 1,700,000
Off balance sheet reserve to nonperforming loans | 23,000 |  | 23,000 |  | 12,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales | 0 | $ 0 | 0 | $ 0 |
Total gains or losses included in earnings | 0 | $ 0 | 0 | 0 |
Total Deferrals Granted [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans and Leases Receivable, Gross | $ 1,400,000,000 |  | $ 1,400,000,000 |  |
Loans and Leases Receivable, Number of Contracts | 6,500 |  | 6,500 |  |
Loans Still in Deferral Period [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans and Leases Receivable, Gross | $ 611,100,000 |  | $ 611,100,000 |  |
Loans to individuals [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Non Accrual Status Of Loans After Number Of Days Past Due |  |  | 150 days |  |
Impaired Loans [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans with modifications to rate and payment due to reamortization |  |  | $ 71,000 | 117,000 |
Nonaccrual Commercial Loans [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans Held for sale, Amount | $ 0 |  | 0 |  | $ 0
Loans and Leases Receivable, Gain (Loss) on Sales, Net |  |  | $ 0 | $ 400,000 |

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