Loans And Allowance for Credit Losses (Credit Quality Indicators Personal Banking 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
Personal Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Total	4,407,606	3,053,435
Consumer Loan [Member]
Credit Quality Indicator [Line Items]
Total	2,475,353	2,196,822
Revolving home equity
Credit Quality Indicator [Line Items]
Total	619,178	375,159
Credit Card Receivable [Member]
Credit Quality Indicator [Line Items]
Total	557,733	589,694
Overdrafts
Credit Quality Indicator [Line Items]
Total	9,510	4,194
Personal Banking Portfolio Segment [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	299,219	911,367
Fiscal Year before Current Fiscal Year	1,123,322	556,650
Two Years before Current Fiscal Year	640,935	575,716
Three Years before Current Fiscal Year	682,623	497,592
Four Years before Current Fiscal Year	736,873	533,968
Prior	2,248,249	1,264,890
Revolving Loans Amortized Cost Basis	2,338,159	1,879,121
Total	8,069,380	6,219,304
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	628	3,416
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	412	3,909
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	593	3,013
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	580	2,121
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	256	768
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	145	388
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	8,805	33,880
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	11,419	47,495
Personal Banking Portfolio Segment [Member] | Personal Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	153,432	386,816
Fiscal Year before Current Fiscal Year	630,463	313,472
Two Years before Current Fiscal Year	428,121	337,531
Three Years before Current Fiscal Year	464,112	364,374
Four Years before Current Fiscal Year	614,434	440,508
Prior	2,106,150	1,201,969
Revolving Loans Amortized Cost Basis	10,894	8,765
Total	4,407,606	3,053,435
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	47
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0	65
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0	416
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0	48
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	7	29
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	0	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	7	605
Personal Banking Portfolio Segment [Member] | Consumer Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	136,277	520,357
Fiscal Year before Current Fiscal Year	492,859	243,178
Two Years before Current Fiscal Year	212,814	238,185
Three Years before Current Fiscal Year	218,511	133,218
Four Years before Current Fiscal Year	122,439	93,460
Prior	142,099	62,921
Revolving Loans Amortized Cost Basis	1,150,354	905,503
Total	2,475,353	2,196,822
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0	894
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	412	3,862
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	593	2,948
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	580	1,705
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	256	720
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff	138	359
Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff	584	2,032
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	2,563	12,520
Personal Banking Portfolio Segment [Member] | Revolving home equity
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	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	619,178	375,159
Total	619,178	375,159
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	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	7	15
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	7	15
Personal Banking Portfolio Segment [Member] | Credit Card Receivable [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	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	557,733	589,694
Total	557,733	589,694
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	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	8,214	31,833
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	8,214	31,833
Personal Banking Portfolio Segment [Member] | Overdrafts
Credit Quality Indicator [Line Items]
Current Fiscal Year	9,510	4,194
Fiscal Year before Current Fiscal Year	0	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	9,510	4,194
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	628	2,522
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	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	628	2,522
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due
Credit Quality Indicator [Line Items]
Current Fiscal Year	299,219	911,180
Fiscal Year before Current Fiscal Year	1,123,056	555,693
Two Years before Current Fiscal Year	640,148	573,729
Three Years before Current Fiscal Year	680,707	493,735
Four Years before Current Fiscal Year	734,113	531,929
Prior	2,242,137	1,259,576
Revolving Loans Amortized Cost Basis	2,326,760	1,868,501
Total	8,046,140	6,194,343
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Personal Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	153,432	386,816
Fiscal Year before Current Fiscal Year	630,463	312,902
Two Years before Current Fiscal Year	427,638	335,950
Three Years before Current Fiscal Year	462,502	360,793
Four Years before Current Fiscal Year	611,820	438,586
Prior	2,100,252	1,196,850
Revolving Loans Amortized Cost Basis	10,894	8,765
Total	4,397,001	3,040,662
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Consumer Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	136,277	520,170
Fiscal Year before Current Fiscal Year	492,593	242,791
Two Years before Current Fiscal Year	212,510	237,779
Three Years before Current Fiscal Year	218,205	132,942
Four Years before Current Fiscal Year	122,293	93,343
Prior	141,885	62,726
Revolving Loans Amortized Cost Basis	1,148,723	903,627
Total	2,472,486	2,193,378
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Revolving home equity
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	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	617,791	374,738
Total	617,791	374,738
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Credit Card Receivable [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	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	549,352	581,371
Total	549,352	581,371
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Overdrafts
Credit Quality Indicator [Line Items]
Current Fiscal Year	9,510	4,194
Fiscal Year before Current Fiscal Year	0	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	9,510	4,194
Personal Banking Portfolio Segment [Member] | Over 90 days past due
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	187
Fiscal Year before Current Fiscal Year	266	957
Two Years before Current Fiscal Year	784	1,987
Three Years before Current Fiscal Year	1,916	3,857
Four Years before Current Fiscal Year	2,760	1,937
Prior	4,799	4,574
Revolving Loans Amortized Cost Basis	11,365	10,620
Total	21,890	24,119
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Personal Real Estate Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	570
Two Years before Current Fiscal Year	480	1,581
Three Years before Current Fiscal Year	1,610	3,581
Four Years before Current Fiscal Year	2,614	1,820
Prior	4,585	4,379
Revolving Loans Amortized Cost Basis	0	0
Total	9,289	11,931
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Consumer Loan [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	187
Fiscal Year before Current Fiscal Year	266	387
Two Years before Current Fiscal Year	304	406
Three Years before Current Fiscal Year	306	276
Four Years before Current Fiscal Year	146	117
Prior	214	195
Revolving Loans Amortized Cost Basis	1,631	1,876
Total	2,867	3,444
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Revolving home equity
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	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	1,353	421
Total	1,353	421
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Credit Card Receivable [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	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	8,381	8,323
Total	8,381	8,323
Personal Banking Portfolio Segment [Member] | Non-Accrual [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	3	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	102
Prior	1,313	740
Revolving Loans Amortized Cost Basis	34	0
Total	1,350	842
Personal Banking Portfolio Segment [Member] | Non-Accrual [Member] | Personal 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	3	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	102
Prior	1,313	740
Revolving Loans Amortized Cost Basis	0	0
Total	$ 1,316	$ 842