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Loans (Summary of Loan Portfolio) (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
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Loans [Line Items] |  |
Total loans, net of unearned income | $ 39,196,485 | $ 34,789,104
Total loans, net of unearned income, percentage | 100.00% | 100.00%
Commercial |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 12,549,164 | $ 11,904,068
Total loans, net of unearned income, percentage | 32.00% | 34.00%
Commercial real estate |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 9,950,947 | $ 8,990,286
Total loans, net of unearned income, percentage | 25.00% | 26.00%
Home equity |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 332,698 | $ 335,155
Total loans, net of unearned income, percentage | 1.00% | 1.00%
Residential real estate |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 2,372,383 | $ 1,637,099
Total loans, net of unearned income, percentage | 6.00% | 5.00%
Premium finance receivables | Property & casualty |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 5,849,459 | $ 4,855,487
Total loans, net of unearned income, percentage | 15.00% | 14.00%
Premium finance receivables | Life insurance |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 8,090,998 | $ 7,042,810
Total loans, net of unearned income, percentage | 21.00% | 20.00%
Consumer and other |  |
Loans [Line Items] |  |
Total loans, net of unearned income | $ 50,836 | $ 24,199
Total loans, net of unearned income, percentage | 0.00% | 0.00%

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