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Fair Values of Assets and Liabilities - Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | $ (831,223) | $ (902,292)
Assets, Fair Value Disclosure | 938,309 | 962,731
Balance, beginning of period | 7,465 | 4,366
Total gains or losses included in earnings | 0 | 198
Total gains or losses included in other comprehensive income | 0 | 0
Purchases | 824 | 2,956
Issuances | 0 | 0
Sales | 0 | 0
Settlements | 0 | (55)
Transfers from Level 3 | 0 | 0
Transfers into Level 3 | 0 | 0
Balance, end of period | 8,289 | 7,465
Other Investments | 12,227 | 16,761
Loans Held-for-sale, Fair Value Disclosure | 33,436 | 15,989
Other Assets, Fair Value Disclosure | 60,981 | 27,689
Other Liabilities, Fair Value Disclosure | 61,308 | 21,469
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 61,308 | 21,469
Equity Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Balance, beginning of period | 1,670 | 1,670
Total gains or losses included in earnings | 0 | 0
Total gains or losses included in other comprehensive income | 0 | 0
Purchases | 0 | 0
Issuances | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Transfers from Level 3 | 0 | 0
Transfers into Level 3 | 0 | 0
Balance, end of period | 1,670 | 1,670
Other Assets [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Balance, beginning of period | 5,795 | 2,696
Total gains or losses included in earnings | 0 | 198
Total gains or losses included in other comprehensive income | 0 | 0
Purchases | 824 | 2,956
Issuances | 0 | 0
Sales | 0 | 0
Settlements | 0 | (55)
Transfers from Level 3 | 0 | 0
Transfers into Level 3 | 0 |
Balance, end of period | 6,619 | 5,795
Corporate Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (24,385) | (23,962)
US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (7,230) | (8,341)
US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Commercial [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (191,180) | (189,133)
Obligations of U.S. Government-Sponsored Enterprises [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (496,033) | (661,947)
Obligations of U.S. Government-Sponsored Enterprises [Member] | Other Government - Sponsored Enterprises [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (100,998) | (1,000)
Obligations of States and Political Subdivisions [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (11,397) | (17,909)
Level 1 [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Assets, Fair Value Disclosure | 0 | 0
Other Investments | 0 |
Loans Held-for-sale, Fair Value Disclosure | 0 | 0
Other Assets, Fair Value Disclosure | 0 | 0
Other Liabilities, Fair Value Disclosure | 0 | 0
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 0 | 0
Level 1 [Member] | Corporate Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Level 1 [Member] | US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Level 1 [Member] | US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Commercial [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Level 1 [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Level 1 [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] | Other Government - Sponsored Enterprises [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Level 1 [Member] | Obligations of States and Political Subdivisions [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (831,223) | (902,292)
Assets, Fair Value Disclosure | 930,020 | 955,266
Other Investments | 10,557 | 15,091
Loans Held-for-sale, Fair Value Disclosure | 33,436 | 15,989
Other Assets, Fair Value Disclosure | 54,362 | 21,894
Other Liabilities, Fair Value Disclosure | 61,308 | 21,469
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 61,308 | 21,469
Fair Value, Inputs, Level 2 [Member] | Corporate Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (24,385) | (23,962)
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (7,230) | (8,341)
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Commercial [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (191,180) | (189,133)
Fair Value, Inputs, Level 2 [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (496,033) | (661,947)
Fair Value, Inputs, Level 2 [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] | Other Government - Sponsored Enterprises [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (100,998) | (1,000)
Fair Value, Inputs, Level 2 [Member] | Obligations of States and Political Subdivisions [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | (11,397) | (17,909)
Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Assets, Fair Value Disclosure | 8,289 | 7,465
Loans Held-for-sale, Fair Value Disclosure | 0 | 0
Other Assets, Fair Value Disclosure | 6,619 | 5,795
Other Liabilities, Fair Value Disclosure | 0 | 0
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Other Investments | 1,670 | 1,670
Fair Value, Inputs, Level 3 [Member] | Corporate Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member] | Mortgage-Backed Securities-Commercial [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Fair Value, Inputs, Level 3 [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] | Mortgage-Backed Securities-Residential [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Fair Value, Inputs, Level 3 [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] | Other Government - Sponsored Enterprises [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | 0 | 0
Fair Value, Inputs, Level 3 [Member] | Obligations of States and Political Subdivisions [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Securities available for sale, at fair value | $ 0 | $ 0

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