Loans And Allowance For Credit Losses (Aging Information On Past Due And Accruing Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	$ 17,226,530	$ 17,080,238
30 - 89 Days Past Due	46,245	96,065
90 Days Past Due and Still Accruing	20,281	21,864
Non-accrual loans	5,784	7,312
Total	17,298,840	17,205,479
Business
Loans And Allowance For Loan Losses [Line Items]
Total	5,994,974	6,019,036
Real estate - construction and land
Loans And Allowance For Loan Losses [Line Items]
Total	1,497,647	1,446,764
Real estate - business
Loans And Allowance For Loan Losses [Line Items]
Total	3,711,602	3,719,306
Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Total	3,039,885	3,026,041
Consumer
Loans And Allowance For Loan Losses [Line Items]
Total	2,119,308	2,077,723
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	322,523	319,894
Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Total	564,388	589,913
Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Total	48,513	6,802
Commercial Portfolio Segment [Member] | Business
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	5,991,756	5,985,713
30 - 89 Days Past Due	1,644	29,087
90 Days Past Due and Still Accruing	536	614
Non-accrual loans	1,038	3,622
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	1,497,325	1,446,764
30 - 89 Days Past Due	322	0
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	3,710,321	3,714,579
30 - 89 Days Past Due	35	4,582
90 Days Past Due and Still Accruing	0	85
Non-accrual loans	1,246	60
Personal Banking Portfolio Segment [Member] | Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	3,015,760	2,999,988
30 - 89 Days Past Due	13,911	14,841
90 Days Past Due and Still Accruing	8,691	9,559
Non-accrual loans	1,523	1,653
Personal Banking Portfolio Segment [Member] | Consumer
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,094,997	2,036,353
30 - 89 Days Past Due	21,409	38,217
90 Days Past Due and Still Accruing	2,902	3,153
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	318,682	315,483
30 - 89 Days Past Due	1,432	1,564
90 Days Past Due and Still Accruing	432	870
Non-accrual loans	1,977	1,977
Personal Banking Portfolio Segment [Member] | Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	549,407	574,805
30 - 89 Days Past Due	7,261	7,525
90 Days Past Due and Still Accruing	7,720	7,583
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	48,282	6,553
30 - 89 Days Past Due	231	249
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	$ 0	$ 0