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Investment Securities, HTM Credit Quality Indicators (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
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Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | $ 3,769,224 | $ 3,860,235
US Treasury Securities |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 1,000 | 999
US States and Political Subdivisions Debt Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 1,664,740 | 1,682,473
Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 900,743 | 941,973
Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 45,180 | 48,979
Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 329,349 | 345,083
Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 775,209 | 780,995
Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 53,005 | 59,733
Not Rated [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 2,060 | 1,155
Not Rated [Member] | US Treasury Securities |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Not Rated [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 2,060 | 1,155
Not Rated [Member] | Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Not Rated [Member] | Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Not Rated [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Not Rated [Member] | Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Not Rated [Member] | Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, AAA Rating [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 2,877,174 | 2,938,090
Fitch, AAA Rating [Member] | US Treasury Securities |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 1,000 | 999
Fitch, AAA Rating [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 772,689 | 760,329
Fitch, AAA Rating [Member] | Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 900,743 | 941,973
Fitch, AAA Rating [Member] | Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 45,180 | 48,979
Fitch, AAA Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 329,349 | 345,083
Fitch, AAA Rating [Member] | Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 775,209 | 780,995
Fitch, AAA Rating [Member] | Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 53,005 | 59,733
Fitch, AA Rating [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 884,498 | 915,303
Fitch, AA Rating [Member] | US Treasury Securities |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, AA Rating [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 884,498 | 915,303
Fitch, AA Rating [Member] | Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, AA Rating [Member] | Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, AA Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, AA Rating [Member] | Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, AA Rating [Member] | Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, A Rating [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 5,492 | 5,687
Fitch, A Rating [Member] | US Treasury Securities |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, A Rating [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 5,492 | 5,687
Fitch, A Rating [Member] | Residential Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, A Rating [Member] | Residential Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, A Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, A Rating [Member] | Commercial Mortgage-Backed Securities [Member] | US Government Sponsored-Enterprise Insured Loans |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | 0 | 0
Fitch, A Rating [Member] | Commercial Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss | $ 0 | $ 0

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