Loans and Allowance for Credit Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 23,970,938	$ 23,921,917	$ 23,404,523
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	3,983,321	3,886,072	3,329,793
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,396,522	1,446,764	1,525,129
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	4,042,797	3,986,943	3,758,455
Construction and Land Development [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,541,773	1,551,091	1,726,916
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	13,006,525	13,051,047	13,064,230
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	9,926,333	9,957,284	10,013,482
Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 3,080,192	$ 3,093,763	$ 3,050,748