Loans and Allowance for Credit Losses (Loans, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 23,404,523	$ 23,114,046	$ 21,323,341
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	3,329,793	3,092,605	2,462,900
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,525,129	1,577,347	1,557,774
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	3,758,455	3,560,991	3,563,299
Construction and Land Development [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,726,916	1,703,592	1,286,655
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	13,064,230	13,179,511	12,452,713
Total Commercial And Industrial [Member] | Commercial Non-Real Estate [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	10,013,482	10,146,453	9,584,480
Total Commercial And Industrial [Member] | Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 3,050,748	$ 3,033,058	$ 2,868,233