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Loans - Schedule of Loan Portfolio (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 | Sep. 30, 2022
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Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 41,446,032 | $ 39,196,485 | $ 38,167,613
Total loans, net of unearned income, percentage | 100.00% | 100.00% | 100.00%
Commercial |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 12,725,473 | $ 12,549,164 | $ 12,259,250
Total loans, net of unearned income, percentage | 31.00% | 32.00% | 32.00%
Commercial real estate |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 10,946,180 | $ 9,950,947 | $ 9,578,184
Total loans, net of unearned income, percentage | 26.00% | 25.00% | 25.00%
Home equity |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 343,258 | $ 332,698 | $ 328,822
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 | $ 2,707,603 | $ 2,372,383 | $ 2,235,459
Total loans, net of unearned income, percentage | 7.00% | 6.00% | 6.00%
Premium finance receivables | Property and casualty insurance |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 6,722,747 | $ 5,849,459 | $ 5,713,340
Total loans, net of unearned income, percentage | 16.00% | 15.00% | 15.00%
Premium finance receivables | Life insurance |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 7,931,808 | $ 8,090,998 | $ 8,004,856
Total loans, net of unearned income, percentage | 19.00% | 21.00% | 21.00%
Consumer and other |  |  |
Loans [Line Items] |  |  |
Total loans, net of unearned income | $ 68,963 | $ 50,836 | $ 47,702
Total loans, net of unearned income, percentage | 0.00% | 0.00% | 0.00%

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