Loans and Allowance for Credit Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 23,911,616	$ 23,921,917	$ 23,789,886
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	4,000,211	3,886,072	3,581,514
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,387,183	1,446,764	1,504,931
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	4,053,812	3,986,943	3,762,428
Construction and Land Development [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,528,393	1,551,091	1,768,252
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	12,942,017	13,051,047	13,172,761
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	9,847,759	9,957,284	10,113,932
Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 3,094,258	$ 3,093,763	$ 3,058,829