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, 2024	Mar. 31, 2023	Dec. 31, 2023
Credit Quality Indicator [Line Items]
Loans charged off	$ 11,165	$ 9,048
Personal Banking Portfolio Segment [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	277,109		$ 984,834
Fiscal Year before Current Fiscal Year	917,975		794,378
Two Years before Current Fiscal Year	755,925		794,244
Three Years before Current Fiscal Year	759,920		839,508
Four Years before Current Fiscal Year	807,783		313,808
Prior	921,655		650,720
Revolving Loans Amortized Cost Basis	1,654,250		1,642,881
Total	6,094,617		6,020,373
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	739		4,729
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	563		2,909
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	554		1,939
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	438		770
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	135		376
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	129		393
Financing Receivable, Revolving, Writeoff	8,291		25,167
Loans charged off	10,849	$ 8,756	36,283
Personal Banking Portfolio Segment [Member] | Real estate - personal
Credit Quality Indicator [Line Items]
Current Fiscal Year	93,720		459,022
Fiscal Year before Current Fiscal Year	439,319		454,064
Two Years before Current Fiscal Year	444,614		535,702
Three Years before Current Fiscal Year	527,938		712,276
Four Years before Current Fiscal Year	696,820		257,360
Prior	829,136		598,997
Revolving Loans Amortized Cost Basis	8,338		8,620
Total	3,039,885		3,026,041
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0		18
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	33		0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	3		23
Financing Receivable, Revolving, Writeoff	0		0
Loans charged off	36		41
Personal Banking Portfolio Segment [Member] | Consumer
Credit Quality Indicator [Line Items]
Current Fiscal Year	134,876		519,010
Fiscal Year before Current Fiscal Year	478,656		340,314
Two Years before Current Fiscal Year	311,311		258,542
Three Years before Current Fiscal Year	231,982		127,232
Four Years before Current Fiscal Year	110,963		56,448
Prior	92,519		51,723
Revolving Loans Amortized Cost Basis	759,001		724,454
Total	2,119,308		2,077,723
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0		926
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	563		2,891
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	521		1,939
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	438		770
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	135		376
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	126		370
Financing Receivable, Revolving, Writeoff	695		1,051
Loans charged off	2,478		8,323
Personal Banking Portfolio Segment [Member] | Revolving Home Equity [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	322,523		319,894
Total	322,523		319,894
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Revolving, Writeoff	0		11
Loans charged off	0		11
Personal Banking Portfolio Segment [Member] | Consumer credit card
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	564,388		589,913
Total	564,388		589,913
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Revolving, Writeoff	7,596		24,105
Loans charged off	7,596		24,105
Personal Banking Portfolio Segment [Member] | Overdrafts
Credit Quality Indicator [Line Items]
Current Fiscal Year	48,513		6,802
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	48,513		6,802
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	739		3,803
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	0		0
Financing Receivable, Revolving, Writeoff	0		0
Loans charged off	739		3,803
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due
Credit Quality Indicator [Line Items]
Current Fiscal Year	274,980		981,124
Fiscal Year before Current Fiscal Year	917,367		792,257
Two Years before Current Fiscal Year	754,025		791,661
Three Years before Current Fiscal Year	758,163		838,650
Four Years before Current Fiscal Year	806,317		313,553
Prior	917,714		647,741
Revolving Loans Amortized Cost Basis	1,642,806		1,630,592
Total	6,071,372		5,995,578
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Real estate - personal
Credit Quality Indicator [Line Items]
Current Fiscal Year	91,591		455,703
Fiscal Year before Current Fiscal Year	438,966		452,153
Two Years before Current Fiscal Year	443,124		533,313
Three Years before Current Fiscal Year	526,377		711,442
Four Years before Current Fiscal Year	695,433		257,159
Prior	825,842		596,439
Revolving Loans Amortized Cost Basis	8,338		8,620
Total	3,029,671		3,014,829
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Consumer
Credit Quality Indicator [Line Items]
Current Fiscal Year	134,876		518,619
Fiscal Year before Current Fiscal Year	478,401		340,104
Two Years before Current Fiscal Year	310,901		258,348
Three Years before Current Fiscal Year	231,786		127,208
Four Years before Current Fiscal Year	110,884		56,394
Prior	91,872		51,302
Revolving Loans Amortized Cost Basis	757,686		722,595
Total	2,116,406		2,074,570
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Revolving Home Equity [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	320,114		317,047
Total	320,114		317,047
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Consumer credit card
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	556,668		582,330
Total	556,668		582,330
Personal Banking Portfolio Segment [Member] | Current to 90 Days Past Due | Overdrafts
Credit Quality Indicator [Line Items]
Current Fiscal Year	48,513		6,802
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	48,513		6,802
Personal Banking Portfolio Segment [Member] | Over 90 days past due
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,129		3,710
Fiscal Year before Current Fiscal Year	608		1,860
Two Years before Current Fiscal Year	1,673		2,416
Three Years before Current Fiscal Year	1,590		858
Four Years before Current Fiscal Year	1,466		98
Prior	2,812		1,911
Revolving Loans Amortized Cost Basis	9,467		10,312
Total	19,745		21,165
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Real estate - personal
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,129		3,319
Fiscal Year before Current Fiscal Year	353		1,650
Two Years before Current Fiscal Year	1,263		2,222
Three Years before Current Fiscal Year	1,394		834
Four Years before Current Fiscal Year	1,387		44
Prior	2,165		1,490
Revolving Loans Amortized Cost Basis	0		0
Total	8,691		9,559
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Consumer
Credit Quality Indicator [Line Items]
Current Fiscal Year	0		391
Fiscal Year before Current Fiscal Year	255		210
Two Years before Current Fiscal Year	410		194
Three Years before Current Fiscal Year	196		24
Four Years before Current Fiscal Year	79		54
Prior	647		421
Revolving Loans Amortized Cost Basis	1,315		1,859
Total	2,902		3,153
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Revolving Home Equity [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	432		870
Total	432		870
Personal Banking Portfolio Segment [Member] | Over 90 days past due | Consumer credit card
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	7,720		7,583
Total	7,720		7,583
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		261
Two Years before Current Fiscal Year	227		167
Three Years before Current Fiscal Year	167		0
Four Years before Current Fiscal Year	0		157
Prior	1,129		1,068
Revolving Loans Amortized Cost Basis	1,977		1,977
Total	3,500		3,630
Personal Banking Portfolio Segment [Member] | Non-Accrual [Member] | Real estate - personal
Credit Quality Indicator [Line Items]
Current Fiscal Year	0		0
Fiscal Year before Current Fiscal Year	0		261
Two Years before Current Fiscal Year	227		167
Three Years before Current Fiscal Year	167		0
Four Years before Current Fiscal Year	0		157
Prior	1,129		1,068
Revolving Loans Amortized Cost Basis	0		0
Total	1,523		1,653
Personal Banking Portfolio Segment [Member] | Non-Accrual [Member] | Revolving Home Equity [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	1,977		1,977
Total	$ 1,977		$ 1,977