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Fair Values of Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Available-for-sale Securities | $ 893,101 |  | $ 909,247
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 | 0 | $ 0 |
Impaired loans considered to be credit risk of non-collection | 100 |  |
Updated appraisal requirement floor | 250 |  |
Other real estate owned | 3,993 |  | 3,935
Financial instrument of credit risk | 300 |  | $ 200
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 |
Total gains or losses included in earnings | 0 | 2,840 |
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 |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 | 0 | 0 |
Total gains or losses included in earnings | $ 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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- Definition Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5162-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4437-111522 + Details
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