Loans And Allowance For Credit Losses (Aging Information On Past Due And Accruing Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	$ 16,460,749	$ 16,229,187
30 - 89 Days Past Due	52,172	49,808
90 Days Past Due and Still Accruing	14,800	15,830
Non-accrual loans	7,801	8,306
Total	16,535,522	16,303,131
Business
Loans And Allowance For Loan Losses [Line Items]
Total	5,704,467	5,661,725
Real estate - construction and land
Loans And Allowance For Loan Losses [Line Items]
Total	1,437,419	1,361,095
Real estate - business
Loans And Allowance For Loan Losses [Line Items]
Total	3,486,543	3,406,981
Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Total	2,952,042	2,918,078
Consumer
Loans And Allowance For Loan Losses [Line Items]
Total	2,094,389	2,059,088
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	295,478	297,207
Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Total	558,669	584,000
Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Total	6,515	14,957
Commercial Portfolio Segment [Member] | Business
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	5,692,966	5,652,710
30 - 89 Days Past Due	4,644	1,759
90 Days Past Due and Still Accruing	496	505
Non-accrual loans	6,361	6,751
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	1,432,344	1,361,095
30 - 89 Days Past Due	4,646	0
90 Days Past Due and Still Accruing	429	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	3,483,425	3,406,207
30 - 89 Days Past Due	2,947	585
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	171	189
Personal Banking Portfolio Segment [Member] | Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,937,474	2,895,742
30 - 89 Days Past Due	8,375	14,289
90 Days Past Due and Still Accruing	4,924	6,681
Non-accrual loans	1,269	1,366
Personal Banking Portfolio Segment [Member] | Consumer
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,067,340	2,031,827
30 - 89 Days Past Due	25,134	25,089
90 Days Past Due and Still Accruing	1,915	2,172
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	293,783	295,303
30 - 89 Days Past Due	846	1,201
90 Days Past Due and Still Accruing	849	703
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	547,228	572,213
30 - 89 Days Past Due	5,254	6,238
90 Days Past Due and Still Accruing	6,187	5,549
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	6,189	14,090
30 - 89 Days Past Due	326	647
90 Days Past Due and Still Accruing	0	220
Non-accrual loans	$ 0	$ 0