Loans - Schedule of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Loans [Line Items]
Total loans, net of unearned income	$ 42,131,831	$ 39,196,485
Total loans, net of unearned income, percentage	100.00%	100.00%
Commercial
Loans [Line Items]
Total loans, net of unearned income	$ 12,832,053	$ 12,549,164
Total loans, net of unearned income, percentage	30.00%	32.00%
Commercial real estate
Loans [Line Items]
Total loans, net of unearned income	$ 11,344,164	$ 9,950,947
Total loans, net of unearned income, percentage	27.00%	25.00%
Home equity
Loans [Line Items]
Total loans, net of unearned income	$ 343,976	$ 332,698
Total loans, net of unearned income, percentage	1.00%	1.00%
Residential real estate
Loans [Line Items]
Total loans, net of unearned income	$ 2,769,666	$ 2,372,383
Total loans, net of unearned income, percentage	7.00%	6.00%
Premium finance receivables | Property & casualty
Loans [Line Items]
Total loans, net of unearned income	$ 6,903,529	$ 5,849,459
Total loans, net of unearned income, percentage	16.00%	15.00%
Premium finance receivables | Life insurance
Loans [Line Items]
Total loans, net of unearned income	$ 7,877,943	$ 8,090,998
Total loans, net of unearned income, percentage	19.00%	21.00%
Consumer and other
Loans [Line Items]
Total loans, net of unearned income	$ 60,500	$ 50,836
Total loans, net of unearned income, percentage	0.00%	0.00%