Loans And Allowance For Credit Losses (Credit Quality Indicators Commercial Loan Portfolio) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Credit Quality Indicator [Line Items]
Total	$ 17,786,767	$ 17,220,103
Business Loan [Member]
Credit Quality Indicator [Line Items]
Total	6,414,792	6,053,820
Real estate - construction and land
Credit Quality Indicator [Line Items]
Total	1,433,652	1,409,901
Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Total	3,745,000	3,661,218
Commercial Portfolio Segment [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,648,181	2,697,978
Fiscal Year before Current Fiscal Year	1,914,137	2,043,809
Two Years before Current Fiscal Year	1,457,939	1,878,607
Three Years before Current Fiscal Year	1,419,047	947,349
Four Years before Current Fiscal Year	706,186	537,261
Prior	954,784	837,905
Revolving Loans Amortized Cost Basis	2,493,170	2,182,030
Total	11,593,444	11,124,939
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0	200
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	368	275
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	516	40
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	165	53
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	10	80
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	1,051	1,387
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	2,110	2,035
Commercial Portfolio Segment [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	1,325,954	1,521,094
Fiscal Year before Current Fiscal Year	980,417	970,070
Two Years before Current Fiscal Year	634,223	624,768
Three Years before Current Fiscal Year	462,602	414,893
Four Years before Current Fiscal Year	284,396	149,674
Prior	383,389	362,309
Revolving Loans Amortized Cost Basis	2,343,811	2,011,012
Total	6,414,792	6,053,820
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0	200
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	344	275
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	116	40
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	165	53
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	10	18
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	1,051	1,387
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	1,686	1,973
Commercial Portfolio Segment [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	332,499	419,782
Fiscal Year before Current Fiscal Year	328,512	445,383
Two Years before Current Fiscal Year	400,580	451,606
Three Years before Current Fiscal Year	323,360	53,462
Four Years before Current Fiscal Year	22,317	3,143
Prior	3,090	2,450
Revolving Loans Amortized Cost Basis	23,294	34,075
Total	1,433,652	1,409,901
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	24	0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	24	0
Commercial Portfolio Segment [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	989,728	757,102
Fiscal Year before Current Fiscal Year	605,208	628,356
Two Years before Current Fiscal Year	423,136	802,233
Three Years before Current Fiscal Year	633,085	478,994
Four Years before Current Fiscal Year	399,473	384,444
Prior	568,305	473,146
Revolving Loans Amortized Cost Basis	126,065	136,943
Total	3,745,000	3,661,218
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	400	0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	0	62
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	400	62
Commercial Portfolio Segment [Member] | Pass [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,603,314	2,680,359
Fiscal Year before Current Fiscal Year	1,860,749	2,004,105
Two Years before Current Fiscal Year	1,417,151	1,801,310
Three Years before Current Fiscal Year	1,331,809	907,172
Four Years before Current Fiscal Year	663,880	515,343
Prior	870,750	720,906
Revolving Loans Amortized Cost Basis	2,318,537	2,051,539
Total	11,066,190	10,680,734
Commercial Portfolio Segment [Member] | Pass [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	1,319,194	1,505,299
Fiscal Year before Current Fiscal Year	974,365	956,449
Two Years before Current Fiscal Year	624,134	596,681
Three Years before Current Fiscal Year	441,379	405,669
Four Years before Current Fiscal Year	275,042	148,483
Prior	380,683	350,106
Revolving Loans Amortized Cost Basis	2,176,145	1,887,596
Total	6,190,942	5,850,283
Commercial Portfolio Segment [Member] | Pass [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	318,318	419,562
Fiscal Year before Current Fiscal Year	328,321	442,720
Two Years before Current Fiscal Year	398,141	451,606
Three Years before Current Fiscal Year	297,506	53,462
Four Years before Current Fiscal Year	4,069	3,143
Prior	3,090	2,450
Revolving Loans Amortized Cost Basis	23,294	34,075
Total	1,372,739	1,407,018
Commercial Portfolio Segment [Member] | Pass [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	965,802	755,498
Fiscal Year before Current Fiscal Year	558,063	604,936
Two Years before Current Fiscal Year	394,876	753,023
Three Years before Current Fiscal Year	592,924	448,041
Four Years before Current Fiscal Year	384,769	363,717
Prior	486,977	368,350
Revolving Loans Amortized Cost Basis	119,098	129,868
Total	3,502,509	3,423,433
Commercial Portfolio Segment [Member] | Special Mention [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	44,549	13,900
Fiscal Year before Current Fiscal Year	50,330	7,978
Two Years before Current Fiscal Year	8,408	21,324
Three Years before Current Fiscal Year	42,669	16,679
Four Years before Current Fiscal Year	2,281	1,906
Prior	4,161	2,363
Revolving Loans Amortized Cost Basis	85,113	34,997
Total	237,511	99,147
Commercial Portfolio Segment [Member] | Special Mention [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	6,442	13,576
Fiscal Year before Current Fiscal Year	4,184	7,978
Two Years before Current Fiscal Year	5,587	8,941
Three Years before Current Fiscal Year	3,955	4,155
Four Years before Current Fiscal Year	1,301	263
Prior	1,738	2,065
Revolving Loans Amortized Cost Basis	85,100	34,997
Total	108,307	71,975
Commercial Portfolio Segment [Member] | Special Mention [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	14,181	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	25,854	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total	40,035	0
Commercial Portfolio Segment [Member] | Special Mention [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	23,926	324
Fiscal Year before Current Fiscal Year	46,146	0
Two Years before Current Fiscal Year	2,821	12,383
Three Years before Current Fiscal Year	12,860	12,524
Four Years before Current Fiscal Year	980	1,643
Prior	2,423	298
Revolving Loans Amortized Cost Basis	13	0
Total	89,169	27,172
Commercial Portfolio Segment [Member] | Substandard [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	318	3,498
Fiscal Year before Current Fiscal Year	2,774	31,679
Two Years before Current Fiscal Year	32,075	55,802
Three Years before Current Fiscal Year	44,445	23,498
Four Years before Current Fiscal Year	39,861	5,344
Prior	65,364	114,468
Revolving Loans Amortized Cost Basis	89,520	95,494
Total	274,357	329,783
Commercial Portfolio Segment [Member] | Substandard [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	318	2,218
Fiscal Year before Current Fiscal Year	1,775	5,596
Two Years before Current Fiscal Year	4,341	19,145
Three Years before Current Fiscal Year	17,268	5,069
Four Years before Current Fiscal Year	8,053	928
Prior	967	10,086
Revolving Loans Amortized Cost Basis	82,566	88,419
Total	115,288	131,461
Commercial Portfolio Segment [Member] | Substandard [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	2,663
Two Years before Current Fiscal Year	2,439	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	18,248	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total	20,687	2,663
Commercial Portfolio Segment [Member] | Substandard [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	1,280
Fiscal Year before Current Fiscal Year	999	23,420
Two Years before Current Fiscal Year	25,295	36,657
Three Years before Current Fiscal Year	27,177	18,429
Four Years before Current Fiscal Year	13,560	4,416
Prior	64,397	104,382
Revolving Loans Amortized Cost Basis	6,954	7,075
Total	138,382	195,659
Commercial Portfolio Segment [Member] | Non-Accrual [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	221
Fiscal Year before Current Fiscal Year	284	47
Two Years before Current Fiscal Year	305	171
Three Years before Current Fiscal Year	124	0
Four Years before Current Fiscal Year	164	14,668
Prior	14,509	168
Revolving Loans Amortized Cost Basis	0	0
Total	15,386	15,275
Commercial Portfolio Segment [Member] | Non-Accrual [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	1
Fiscal Year before Current Fiscal Year	93	47
Two Years before Current Fiscal Year	161	1
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	1	52
Revolving Loans Amortized Cost Basis	0	0
Total	255	101
Commercial Portfolio Segment [Member] | Non-Accrual [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	220
Fiscal Year before Current Fiscal Year	191	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total	191	220
Commercial Portfolio Segment [Member] | Non-Accrual [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	144	170
Three Years before Current Fiscal Year	124	0
Four Years before Current Fiscal Year	164	14,668
Prior	14,508	116
Revolving Loans Amortized Cost Basis	0	0
Total	$ 14,940	$ 14,954