Loans And Allowance For Credit Losses (Aging Information On Past Due And Accruing Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	$ 15,629,037	$ 15,116,475
30 - 89 Days Past Due	37,764	39,001
90 Days Past Due and Still Accruing	11,909	11,726
Non-accrual loans	7,917	9,157
Total	15,686,627	15,176,359
Business
Loans And Allowance For Loan Losses [Line Items]
Total	5,441,592	5,303,535
Real estate - construction and land
Loans And Allowance For Loan Losses [Line Items]
Total	1,266,260	1,118,266
Real estate - business
Loans And Allowance For Loan Losses [Line Items]
Total	3,215,578	3,058,837
Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Total	2,836,835	2,805,401
Consumer
Loans And Allowance For Loan Losses [Line Items]
Total	2,089,592	2,032,225
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	271,854	275,945
Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Total	558,102	575,410
Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Total	6,814	6,740
Commercial Portfolio Segment [Member] | Business
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	5,432,582	5,292,125
30 - 89 Days Past Due	2,278	3,621
90 Days Past Due and Still Accruing	418	477
Non-accrual loans	6,314	7,312
Commercial Portfolio Segment [Member] | Real estate - construction and land
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	1,266,203	1,117,434
30 - 89 Days Past Due	57	832
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	0	0
Commercial Portfolio Segment [Member] | Real estate - business
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	3,212,739	3,058,566
30 - 89 Days Past Due	2,313	57
90 Days Past Due and Still Accruing	359	0
Non-accrual loans	167	214
Personal Banking Portfolio Segment [Member] | Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,821,955	2,796,662
30 - 89 Days Past Due	9,762	4,125
90 Days Past Due and Still Accruing	3,682	2,983
Non-accrual loans	1,436	1,631
Personal Banking Portfolio Segment [Member] | Consumer
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,069,092	2,005,556
30 - 89 Days Past Due	18,001	24,458
90 Days Past Due and Still Accruing	2,499	2,211
Non-accrual loans	0	0
Personal Banking Portfolio Segment [Member] | Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	270,572	274,372
30 - 89 Days Past Due	464	772
90 Days Past Due and Still Accruing	818	801
Non-accrual loans	0	0
Personal Banking Portfolio Segment [Member] | Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	549,589	565,335
30 - 89 Days Past Due	4,385	4,821
90 Days Past Due and Still Accruing	4,128	5,254
Non-accrual loans	0	0
Personal Banking Portfolio Segment [Member] | Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	6,305	6,425
30 - 89 Days Past Due	504	315
90 Days Past Due and Still Accruing	5	0
Non-accrual loans	$ 0	$ 0