Loans And Allowance for Credit Losses (Credit Quality Indicators Personal Banking Loan Portfolio) (Details) - Personal Banking Portfolio Segment [Member] $ in Thousands	Mar. 31, 2020 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 363,079
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,106,191
Financing Receivable, Originated Two Years before Latest Fiscal Year	548,769
Financing Receivable, Originated Three Years before Latest Fiscal Year	467,167
Financing Receivable, Originated Four Years before Latest Fiscal Year	419,042
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	886,996
Financing Receivable, Revolving	1,674,993
Financing Receivable, before Allowance for Credit Loss, Total	5,466,237
Real Estate - Personal [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	230,746
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	624,231
Financing Receivable, Originated Two Years before Latest Fiscal Year	298,203
Financing Receivable, Originated Three Years before Latest Fiscal Year	273,613
Financing Receivable, Originated Four Years before Latest Fiscal Year	292,740
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	733,444
Financing Receivable, Revolving	11,842
Financing Receivable, before Allowance for Credit Loss, Total	2,464,819
Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	129,190
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	481,960
Financing Receivable, Originated Two Years before Latest Fiscal Year	250,566
Financing Receivable, Originated Three Years before Latest Fiscal Year	193,554
Financing Receivable, Originated Four Years before Latest Fiscal Year	126,302
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	153,552
Financing Receivable, Revolving	606,663
Financing Receivable, before Allowance for Credit Loss, Total	1,941,787
Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	349,735
Financing Receivable, before Allowance for Credit Loss, Total	349,735
Consumer Credit Card [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	706,753
Financing Receivable, before Allowance for Credit Loss, Total	706,753
Overdrafts [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	3,143
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss, Total	3,143
Current to 90 Days Past Due
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	363,079
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,105,226
Financing Receivable, Originated Two Years before Latest Fiscal Year	548,592
Financing Receivable, Originated Three Years before Latest Fiscal Year	466,794
Financing Receivable, Originated Four Years before Latest Fiscal Year	417,992
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	884,195
Financing Receivable, Revolving	1,662,689
Financing Receivable, before Allowance for Credit Loss, Total	5,448,567
Current to 90 Days Past Due | Real Estate - Personal [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	230,746
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	623,695
Financing Receivable, Originated Two Years before Latest Fiscal Year	298,166
Financing Receivable, Originated Three Years before Latest Fiscal Year	273,521
Financing Receivable, Originated Four Years before Latest Fiscal Year	291,938
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	731,052
Financing Receivable, Revolving	11,702
Financing Receivable, before Allowance for Credit Loss, Total	2,460,820
Current to 90 Days Past Due | Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	129,190
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	481,531
Financing Receivable, Originated Two Years before Latest Fiscal Year	250,426
Financing Receivable, Originated Three Years before Latest Fiscal Year	193,273
Financing Receivable, Originated Four Years before Latest Fiscal Year	126,054
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	153,143
Financing Receivable, Revolving	605,960
Financing Receivable, before Allowance for Credit Loss, Total	1,939,577
Current to 90 Days Past Due | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	349,200
Financing Receivable, before Allowance for Credit Loss, Total	349,200
Current to 90 Days Past Due | Consumer Credit Card [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	695,827
Financing Receivable, before Allowance for Credit Loss, Total	695,827
Current to 90 Days Past Due | Overdrafts [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	3,143
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss, Total	3,143
Over 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	964
Financing Receivable, Originated Two Years before Latest Fiscal Year	177
Financing Receivable, Originated Three Years before Latest Fiscal Year	326
Financing Receivable, Originated Four Years before Latest Fiscal Year	982
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,174
Financing Receivable, Revolving	12,304
Financing Receivable, before Allowance for Credit Loss, Total	15,927
Over 90 days past due | Real Estate - Personal [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	535
Financing Receivable, Originated Two Years before Latest Fiscal Year	37
Financing Receivable, Originated Three Years before Latest Fiscal Year	45
Financing Receivable, Originated Four Years before Latest Fiscal Year	734
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	765
Financing Receivable, Revolving	140
Financing Receivable, before Allowance for Credit Loss, Total	2,256
Over 90 days past due | Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	429
Financing Receivable, Originated Two Years before Latest Fiscal Year	140
Financing Receivable, Originated Three Years before Latest Fiscal Year	281
Financing Receivable, Originated Four Years before Latest Fiscal Year	248
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	409
Financing Receivable, Revolving	703
Financing Receivable, before Allowance for Credit Loss, Total	2,210
Over 90 days past due | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	535
Financing Receivable, before Allowance for Credit Loss, Total	535
Over 90 days past due | Consumer Credit Card [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	10,926
Financing Receivable, before Allowance for Credit Loss, Total	10,926
Over 90 days past due | Overdrafts [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss, Total	0
Non-Accrual [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	47
Financing Receivable, Originated Four Years before Latest Fiscal Year	68
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,627
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss, Total	1,743
Non-Accrual [Member] | Real Estate - Personal [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	47
Financing Receivable, Originated Four Years before Latest Fiscal Year	68
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,627
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss, Total	$ 1,743