Loans and Allowance for Credit Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 22,585,585	$ 21,134,282	$ 20,886,015
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,843,723	2,423,890	2,351,053
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,575,505	1,583,390	1,623,116
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	3,686,540	3,464,626	3,467,939
Construction and Land Development [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,541,257	1,228,670	1,213,991
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	12,938,560	12,433,706	12,229,916
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	9,905,427	9,612,460	9,416,990
Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 3,033,133	$ 2,821,246	$ 2,812,926