Loans And Allowance For Credit Losses (Summary Classification Of Held To Maturity Loan Portfolio) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	$ 15,459,014	$ 15,176,359
Business
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	5,508,508	5,303,535
Real estate - construction and land
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	1,144,411	1,118,266
Real estate - business
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	3,109,668	3,058,837
Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	2,820,076	2,805,401
Consumer
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	2,053,160	2,032,225
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	264,401	275,945
Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	544,579	575,410
Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Held for Investment Loans	$ 14,211	$ 6,740