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Investment Securities - Allowance for Credit Losses HTM (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023
Held-to-maturity |  |  |  |
Beginning balance | $ 3,214 | $ 3,214 | $ 3,214 | $ 1,388
Provision for credit loss expense | 0 | 0 | 0 | 1,826
Net increase (decrease) in allowance on previously impaired securities | 0 | 0 | 0 | 0
Ending balance | 3,214 | 3,214 | 3,214 | 3,214
State and political subdivisions |  |  |  |
Held-to-maturity |  |  |  |
Beginning balance | 191 | 934 | 2,006 | 110
Provision for credit loss expense | 0 | 0 | 0 | 824
Net increase (decrease) in allowance on previously impaired securities | 36 | 586 | (1,779) | 586
Ending balance | 227 | 1,520 | 227 | 1,520
Other securities |  |  |  |
Held-to-maturity |  |  |  |
Beginning balance | 3,023 | 2,280 | 1,208 | 1,278
Provision for credit loss expense | 0 | 0 | 0 | 1,002
Net increase (decrease) in allowance on previously impaired securities | (36) | (586) | 1,779 | (586)
Ending balance | $ 2,987 | $ 1,694 | $ 2,987 | $ 1,694

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- Definition Amount, excluding accrued interest, of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
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- Definition Amount of expense (reversal of expense) for expected credit loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
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- Definition Amount, excluding accrued interest, of increase (decrease) in allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
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