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Allowance for Credit Losses - Schedule of Aging of the Company's Loan Portfolio (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Dec. 31, 2024 | Mar. 31, 2024
--- | --- | --- | ---
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | $ 151,203 | $ 154,641 | $ 122,408
Loans, net of unearned income | 48,708,390 | 48,055,037 | 43,230,706
Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 0 | 0 | 0
Loans, net of unearned income | 123,742 | 156,756 | 143,350
Commercial, industrial and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 70,560 | 73,490 | 31,740
Loans, net of unearned income | 15,931,326 | 15,574,551 | 13,503,481
Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 12,914,901 | 12,903,944 | 11,633,437
Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 3,613 | 2,282 | 1,627
Loans, net of unearned income | 2,448,881 | 2,434,081 | 2,150,314
Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 22,574 | 18,760 | 37,635
Loans, net of unearned income | 10,466,020 | 10,469,863 | 9,483,123
Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 2,070 | 1,117 | 838
Loans, net of unearned income | 455,683 | 445,028 | 340,349
Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,685,159 | 3,612,765 | 2,890,266
Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 22,522 | 23,762 | 17,901
Loans, net of unearned income | 3,561,417 | 3,456,009 | 2,746,916
Premium finance receivables | Property and casualty insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 29,846 | 28,797 | 32,648
Loans, net of unearned income | 7,239,862 | 7,272,042 | 6,940,019
Premium finance receivables | Life insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 0 | 6,431 | 0
Loans, net of unearned income | 8,365,140 | 8,147,145 | 7,872,033
Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 18 | 2 | 19
Loans, net of unearned income | 116,319 | 99,562 | 51,121
Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 151,203 | 154,641 | 122,408
Loans, net of unearned income | 48,584,648 | 47,898,281 | 43,087,356
90+ days and still accruing |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 51,647 | 50,134 | 76,168
90+ days and still accruing | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 30,460 | 33,952 | 50,217
90+ days and still accruing | Commercial, industrial and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 46 | 104 | 27
90+ days and still accruing | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Premium finance receivables | Property and casualty insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 18,081 | 16,031 | 25,877
90+ days and still accruing | Premium finance receivables | Life insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 2,962 | 0 | 0
90+ days and still accruing | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 98 | 47 | 47
90+ days and still accruing | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 21,187 | 16,182 | 25,951
60-89 days past due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 56,496 | 164,988 | 94,945
60-89 days past due | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 1,457 | 618 | 0
60-89 days past due | Commercial, industrial and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 15,243 | 54,844 | 30,248
60-89 days past due | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 820 | 1,339 | 818
60-89 days past due | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 6,175 | 9,182 | 15,895
60-89 days past due | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 984 | 1,233 | 212
60-89 days past due | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 1,351 | 5,708 | 0
60-89 days past due | Premium finance receivables | Property and casualty insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 19,717 | 19,042 | 15,274
60-89 days past due | Premium finance receivables | Life insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 10,587 | 72,963 | 32,482
60-89 days past due | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 162 | 59 | 16
60-89 days past due | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 55,039 | 164,370 | 94,945
30-59 days past due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 295,446 | 252,223 | 297,976
30-59 days past due | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 2,125 | 2,335 | 1,047
30-59 days past due | Commercial, industrial and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 97,397 | 92,551 | 77,715
30-59 days past due | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,994 | 4,634 | 7,066
30-59 days past due | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 79,659 | 26,132 | 25,932
30-59 days past due | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,403 | 2,148 | 1,617
30-59 days past due | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 38,943 | 18,917 | 24,523
30-59 days past due | Premium finance receivables | Property and casualty insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 39,459 | 68,219 | 59,729
30-59 days past due | Premium finance receivables | Life insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 29,924 | 36,405 | 100,137
30-59 days past due | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 542 | 882 | 210
30-59 days past due | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 293,321 | 249,888 | 296,929
Current |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 48,153,598 | 47,433,051 | 42,639,209
Current | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 89,700 | 119,851 | 92,086
Current | Commercial, industrial and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 15,748,080 | 15,353,562 | 13,363,751
Current | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 2,440,454 | 2,425,826 | 2,140,803
Current | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 10,357,612 | 10,415,789 | 9,403,661
Current | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 449,226 | 440,530 | 337,682
Current | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,498,601 | 3,407,622 | 2,704,492
Current | Premium finance receivables | Property and casualty insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 7,132,759 | 7,139,953 | 6,806,491
Current | Premium finance receivables | Life insurance loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 8,321,667 | 8,031,346 | 7,739,414
Current | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 115,499 | 98,572 | 50,829
Current | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | $ 48,063,898 | $ 47,313,200 | $ 42,547,123

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