Loans And Allowance For Credit Losses (Credit Quality Indicators Commercial Loan Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Credit Quality Indicator [Line Items]
Total	$ 20,461,064	$ 17,771,263
Business Loan [Member]
Credit Quality Indicator [Line Items]
Total	6,750,356	6,439,380
Real estate - construction and land
Credit Quality Indicator [Line Items]
Total	1,581,789	1,438,012
Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Total	4,059,539	3,674,567
Commercial Portfolio Segment [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	926,963	3,575,521
Fiscal Year before Current Fiscal Year	3,504,960	1,592,005
Two Years before Current Fiscal Year	1,585,958	1,277,215
Three Years before Current Fiscal Year	1,203,815	1,201,714
Four Years before Current Fiscal Year	1,171,174	653,886
Prior	1,404,450	797,985
Revolving Loans Amortized Cost Basis	2,594,364	2,453,633
Total	12,391,684	11,551,959
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	429
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0	516
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	32	165
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	55	2
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	5,440	10
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	272	1,423
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	5,799	2,545
Commercial Portfolio Segment [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	440,569	1,717,805
Fiscal Year before Current Fiscal Year	1,575,861	852,790
Two Years before Current Fiscal Year	825,441	575,767
Three Years before Current Fiscal Year	547,916	434,267
Four Years before Current Fiscal Year	413,136	257,307
Prior	552,812	338,556
Revolving Loans Amortized Cost Basis	2,394,621	2,262,888
Total	6,750,356	6,439,380
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	389
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0	116
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	32	165
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	55	2
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	24	10
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	272	1,423
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	383	2,105
Commercial Portfolio Segment [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	156,781	464,150
Fiscal Year before Current Fiscal Year	562,138	283,778
Two Years before Current Fiscal Year	325,625	381,821
Three Years before Current Fiscal Year	310,634	265,189
Four Years before Current Fiscal Year	197,155	22,105
Prior	6,032	2,860
Revolving Loans Amortized Cost Basis	23,424	18,109
Total	1,581,789	1,438,012
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	40
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	0	40
Commercial Portfolio Segment [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	329,613	1,393,566
Fiscal Year before Current Fiscal Year	1,366,961	455,437
Two Years before Current Fiscal Year	434,892	319,627
Three Years before Current Fiscal Year	345,265	502,258
Four Years before Current Fiscal Year	560,883	374,474
Prior	845,606	456,569
Revolving Loans Amortized Cost Basis	176,319	172,636
Total	4,059,539	3,674,567
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	0	400
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	5,416	0
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	5,416	400
Commercial Portfolio Segment [Member] | Pass [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	926,963	3,489,006
Fiscal Year before Current Fiscal Year	3,414,861	1,557,881
Two Years before Current Fiscal Year	1,555,545	1,257,226
Three Years before Current Fiscal Year	1,128,349	1,118,999
Four Years before Current Fiscal Year	1,096,536	616,188
Prior	1,338,881	728,797
Revolving Loans Amortized Cost Basis	2,444,305	2,313,565
Total	11,905,440	11,081,662
Commercial Portfolio Segment [Member] | Pass [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	440,569	1,704,299
Fiscal Year before Current Fiscal Year	1,543,502	847,973
Two Years before Current Fiscal Year	805,900	568,361
Three Years before Current Fiscal Year	543,237	416,732
Four Years before Current Fiscal Year	398,031	252,398
Prior	548,931	336,662
Revolving Loans Amortized Cost Basis	2,254,771	2,129,247
Total	6,534,941	6,255,672
Commercial Portfolio Segment [Member] | Pass [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	156,781	450,046
Fiscal Year before Current Fiscal Year	548,196	283,778
Two Years before Current Fiscal Year	325,625	379,456
Three Years before Current Fiscal Year	252,478	239,314
Four Years before Current Fiscal Year	171,259	3,857
Prior	6,032	2,860
Revolving Loans Amortized Cost Basis	23,424	18,109
Total	1,483,795	1,377,420
Commercial Portfolio Segment [Member] | Pass [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	329,613	1,334,661
Fiscal Year before Current Fiscal Year	1,323,163	426,130
Two Years before Current Fiscal Year	424,020	309,409
Three Years before Current Fiscal Year	332,634	462,953
Four Years before Current Fiscal Year	527,246	359,933
Prior	783,918	389,275
Revolving Loans Amortized Cost Basis	166,110	166,209
Total	3,886,704	3,448,570
Commercial Portfolio Segment [Member] | Special Mention [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	86,419
Fiscal Year before Current Fiscal Year	67,589	31,572
Two Years before Current Fiscal Year	9,923	6,233
Three Years before Current Fiscal Year	57,917	13,757
Four Years before Current Fiscal Year	2,512	1,858
Prior	466	3,340
Revolving Loans Amortized Cost Basis	43,995	47,599
Total	182,402	190,778
Commercial Portfolio Segment [Member] | Special Mention [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	13,410
Fiscal Year before Current Fiscal Year	10,239	4,149
Two Years before Current Fiscal Year	24	2,661
Three Years before Current Fiscal Year	698	1,536
Four Years before Current Fiscal Year	130	893
Prior	400	1,375
Revolving Loans Amortized Cost Basis	40,163	47,568
Total	51,654	71,592
Commercial Portfolio Segment [Member] | Special Mention [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	14,104
Fiscal Year before Current Fiscal Year	13,942	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	55,816	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total	69,758	14,104
Commercial Portfolio Segment [Member] | Special Mention [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	58,905
Fiscal Year before Current Fiscal Year	43,408	27,423
Two Years before Current Fiscal Year	9,899	3,572
Three Years before Current Fiscal Year	1,403	12,221
Four Years before Current Fiscal Year	2,382	965
Prior	66	1,965
Revolving Loans Amortized Cost Basis	3,832	31
Total	60,990	105,082
Commercial Portfolio Segment [Member] | Substandard [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	96
Fiscal Year before Current Fiscal Year	22,460	2,503
Two Years before Current Fiscal Year	20,454	13,724
Three Years before Current Fiscal Year	17,435	68,792
Four Years before Current Fiscal Year	72,002	35,687
Prior	55,857	51,340
Revolving Loans Amortized Cost Basis	106,064	92,469
Total	294,272	264,611
Commercial Portfolio Segment [Member] | Substandard [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	96
Fiscal Year before Current Fiscal Year	22,070	619
Two Years before Current Fiscal Year	19,481	4,713
Three Years before Current Fiscal Year	3,867	15,957
Four Years before Current Fiscal Year	14,975	4,016
Prior	3,480	519
Revolving Loans Amortized Cost Basis	99,687	86,073
Total	163,560	111,993
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	0
Two Years before Current Fiscal Year	0	2,365
Three Years before Current Fiscal Year	2,340	25,875
Four Years before Current Fiscal Year	25,896	18,248
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total	28,236	46,488
Commercial Portfolio Segment [Member] | Substandard [Member] | Business Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	390	1,884
Two Years before Current Fiscal Year	973	6,646
Three Years before Current Fiscal Year	11,228	26,960
Four Years before Current Fiscal Year	31,131	13,423
Prior	52,377	50,821
Revolving Loans Amortized Cost Basis	6,377	6,396
Total	102,476	106,130
Commercial Portfolio Segment [Member] | Non-Accrual [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	50	49
Two Years before Current Fiscal Year	36	32
Three Years before Current Fiscal Year	114	166
Four Years before Current Fiscal Year	124	153
Prior	9,246	14,508
Revolving Loans Amortized Cost Basis	0	0
Total	9,570	14,908
Commercial Portfolio Segment [Member] | Non-Accrual [Member] | Business Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	50	49
Two Years before Current Fiscal Year	36	32
Three Years before Current Fiscal Year	114	42
Four Years before Current Fiscal Year	0	0
Prior	1	0
Revolving Loans Amortized Cost Basis	0	0
Total	201	123
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	0	0
Three Years before Current Fiscal Year	0	124
Four Years before Current Fiscal Year	124	153
Prior	9,245	14,508
Revolving Loans Amortized Cost Basis	0	0
Total	$ 9,369	$ 14,785