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Loans - Schedule of Loan Portfolio (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Dec. 31, 2024 | Mar. 31, 2024
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Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 48,708,390 | $ 48,055,037 | $ 43,230,706
Total loans, net of unearned income, percentage | 100.00% | 100.00% | 100.00%
Commercial |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 15,931,326 | $ 15,574,551 | $ 13,503,481
Total loans, net of unearned income, percentage | 33.00% | 32.00% | 31.00%
Commercial real estate |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 12,914,901 | $ 12,903,944 | $ 11,633,437
Total loans, net of unearned income, percentage | 26.00% | 27.00% | 27.00%
Home equity |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 455,683 | $ 445,028 | $ 340,349
Total loans, net of unearned income, percentage | 1.00% | 1.00% | 1.00%
Residential real estate |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 3,685,159 | $ 3,612,765 | $ 2,890,266
Total loans, net of unearned income, percentage | 8.00% | 8.00% | 7.00%
Premium finance receivables | Premium finance receivables—property & casualty |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 7,239,862 | $ 7,272,042 | $ 6,940,019
Total loans, net of unearned income, percentage | 15.00% | 15.00% | 16.00%
Premium finance receivables | Premium finance receivables—life insurance |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 8,365,140 | $ 8,147,145 | $ 7,872,033
Total loans, net of unearned income, percentage | 17.00% | 17.00% | 18.00%
Consumer and other |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 116,319 | $ 99,562 | $ 51,121
Total loans, net of unearned income, percentage | 0.00% | 0.00% | 0.00%

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