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Investment Securities Available for Sale - Narrative (Details) | Apr. 01, 2024 USD ($) | Mar. 31, 2024 USD ($) security | Dec. 31, 2023 USD ($)
--- | --- | --- | ---
Financing Receivable, Impaired [Line Items] |  |  |
Gross unrealized loss |  | $ 1,465,692,000 | $ 1,334,132,000
Investment securities in a loss position for less than twelve months | security |  | 29 |
Investment securities in a loss position for twelve months or longer | security |  | 353 |
Allowance for credit loss |  | $ 0 |
Subsequent Event |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
Debt securities transferred from available for sale to held to maturity | $ 3,420,000,000 |  |
Gross unrealized loss | $ 708,500,000 |  |
Collateral Pledged |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
Pledged to secure deposits |  | $ 5,020,000,000.00 | $ 5,190,000,000

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- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 + Details
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