Loans - Schedule of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Loans [Line Items]
Total loans, net of unearned income	$ 48,055,037	$ 42,131,831
Total loans, net of unearned income, percentage	100.00%	100.00%
Commercial
Loans [Line Items]
Total loans, net of unearned income	$ 15,574,551	$ 12,832,053
Total loans, net of unearned income, percentage	32.00%	30.00%
Commercial real estate
Loans [Line Items]
Total loans, net of unearned income	$ 12,903,944	$ 11,344,164
Total loans, net of unearned income, percentage	27.00%	27.00%
Home equity
Loans [Line Items]
Total loans, net of unearned income	$ 445,028	$ 343,976
Total loans, net of unearned income, percentage	1.00%	1.00%
Residential real estate
Loans [Line Items]
Total loans, net of unearned income	$ 3,612,765	$ 2,769,666
Total loans, net of unearned income, percentage	8.00%	7.00%
Premium finance receivables | Premium finance receivables—property & casualty
Loans [Line Items]
Total loans, net of unearned income	$ 7,272,042	$ 6,903,529
Total loans, net of unearned income, percentage	15.00%	16.00%
Premium finance receivables | Premium finance receivables—life insurance
Loans [Line Items]
Total loans, net of unearned income	$ 8,147,145	$ 7,877,943
Total loans, net of unearned income, percentage	17.00%	19.00%
Consumer and other
Loans [Line Items]
Total loans, net of unearned income	$ 99,562	$ 60,500
Total loans, net of unearned income, percentage	0.00%	0.00%