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Investment Securities - Additional Information (Detail) $ in Thousands | 12 Months Ended
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Dec. 31, 2023 USD ($) Security | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items] |  |  |
Securities available for sale | $ 1,020,986 | $ 762,661 |
Other investments | 44,700 | 25,200 |
Equity Securities, FV-NI | $ 6,200 | 1,200 |
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | Security | 207 |  |
Equity Securities, FV-NI, Gain (Loss) | $ 0 | 0 |
Total debt securities, Amortized Cost | 1,138,425 | 898,702 |
Debt Securities, Available-for-Sale | 1,020,986 | 762,661 |
Obligations of U.S. Government-Sponsored Enterprises [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Securities available for sale | 494,600 |  |
Total debt securities, Amortized Cost | 559,800 |  |
Debt Securities, Available-for-Sale | 494,600 |  |
Held-to-maturity Securities [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Deposit Liabilities, Collateral Issued, Financial Instruments | 98,100 | 368,800 |
Available-for-sale Securities [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Deposit Liabilities, Collateral Issued, Financial Instruments | 386,500 | 626,700 |
Mortgage - Backed Securities - Residential [Member] | Obligations of U.S. Government-Sponsored Enterprises [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Securities available for sale | 494,599 | 448,989 |
Total debt securities, Amortized Cost | 559,769 | 527,777 |
Debt Securities, Available-for-Sale | 494,599 | 448,989 |
Corporate Securities [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Securities available for sale | 48,412 | 29,204 |
Total debt securities, Amortized Cost | 51,886 | 32,010 |
Debt Securities, Available-for-Sale | 48,412 | 29,204 |
Sales [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Gross Gains | 0 | 0 | $ 0
Calls And Maturities [Member] |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Gross Gains | $ 0 | $ 2 | $ 16

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- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479130/326-30-45-1 + Details
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