Loans And Allowance For Credit Losses (Aging Information On Past Due And Accruing Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	$ 17,697,236	$ 17,093,789
30 - 89 Days Past Due	51,742	83,520
90 Days Past Due and Still Accruing	21,536	24,516
Non-accrual loans	16,253	18,278
Total	17,786,767	17,220,103
Business Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	6,414,792	6,053,820
Real estate - construction and land
Loans And Allowance For Loan Losses [Line Items]
Total	1,433,652	1,409,901
Business Real Estate Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	3,745,000	3,661,218
Personal Real Estate Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	3,070,980	3,058,195
Consumer Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	2,171,599	2,073,123
Revolving home equity
Loans And Allowance For Loan Losses [Line Items]
Total	364,241	356,650
Credit Card Receivable [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	575,317	595,930
Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Total	11,186	11,266
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	11,593,444	11,124,939
Commercial Portfolio Segment [Member] | Business Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	6,407,415	6,051,654
30 - 89 Days Past Due	6,323	1,501
90 Days Past Due and Still Accruing	799	564
Non-accrual loans	255	101
Total	6,414,792	6,053,820
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	1,433,078	1,409,681
30 - 89 Days Past Due	383	0
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	191	220
Total	1,433,652	1,409,901
Commercial Portfolio Segment [Member] | Business Real Estate Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	3,727,793	3,640,643
30 - 89 Days Past Due	2,267	5,621
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	14,940	14,954
Total	3,745,000	3,661,218
Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	6,193,323	6,095,164
Personal Banking Portfolio Segment [Member] | Personal Real Estate Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	3,054,874	3,021,017
30 - 89 Days Past Due	5,573	25,267
90 Days Past Due and Still Accruing	9,666	10,885
Non-accrual loans	867	1,026
Total	3,070,980	3,058,195
Personal Banking Portfolio Segment [Member] | Consumer Loan [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,140,052	2,029,115
30 - 89 Days Past Due	28,754	40,398
90 Days Past Due and Still Accruing	2,793	3,610
Non-accrual loans	0	0
Total	2,171,599	2,073,123
Personal Banking Portfolio Segment [Member] | Revolving home equity
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	362,863	351,056
30 - 89 Days Past Due	760	2,798
90 Days Past Due and Still Accruing	618	819
Non-accrual loans	0	1,977
Total	364,241	356,650
Personal Banking Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	560,209	579,670
30 - 89 Days Past Due	7,448	7,622
90 Days Past Due and Still Accruing	7,660	8,638
Non-accrual loans	0	0
Total	575,317	595,930
Personal Banking Portfolio Segment [Member] | Overdrafts
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	10,952	10,953
30 - 89 Days Past Due	234	313
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	0	0
Total	$ 11,186	$ 11,266