Loans And Allowance For Credit Losses (Credit Quality Indicators of the Commercial Loan Portfolio) (Details) - Commercial Portfolio Segment [Member] $ in Thousands	Dec. 31, 2020 USD ($)
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 3,992,080
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,034,638
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	927,791
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	714,477
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	545,687
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	547,950
Financing Receivable, Revolving	1,831,176
Financing Receivable, before Allowance for Credit Loss	10,593,799
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,530,896
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,014,800
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	463,062
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	334,054
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	172,528
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	300,317
Financing Receivable, Revolving	1,730,430
Financing Receivable, before Allowance for Credit Loss	6,546,087
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	514,148
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	330,480
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	72,758
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	50,735
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,426
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,692
Financing Receivable, Revolving	27,356
Financing Receivable, before Allowance for Credit Loss	1,021,595
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	947,036
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	689,358
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	391,971
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	329,688
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	348,733
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	245,941
Financing Receivable, Revolving	73,390
Financing Receivable, before Allowance for Credit Loss	3,026,117
Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	3,846,461
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,962,947
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	832,154
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	573,884
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	501,474
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	482,830
Financing Receivable, Revolving	1,714,832
Financing Receivable, before Allowance for Credit Loss	9,914,582
Pass [Member] \| Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,472,419
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	966,068
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	438,557
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	329,207
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	163,357
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	281,604
Financing Receivable, Revolving	1,619,680
Financing Receivable, before Allowance for Credit Loss	6,270,892
Pass [Member] \| Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	483,302
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	330,480
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	56,747
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,021
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,426
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,692
Financing Receivable, Revolving	27,356
Financing Receivable, before Allowance for Credit Loss	927,024
Pass [Member] \| Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	890,740
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	666,399
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	336,850
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	241,656
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	313,691
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	199,534
Financing Receivable, Revolving	67,796
Financing Receivable, before Allowance for Credit Loss	2,716,666
Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	67,240
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	48,480
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	64,704
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	42,910
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	22,595
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,973
Financing Receivable, Revolving	44,751
Financing Receivable, before Allowance for Credit Loss	293,653
Special Mention [Member] \| Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	28,612
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	26,746
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	14,102
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,781
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	5,091
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,664
Financing Receivable, Revolving	41,749
Financing Receivable, before Allowance for Credit Loss	119,745
Special Mention [Member] \| Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	29,692
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,022
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	34,532
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss	65,246
Special Mention [Member] \| Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	8,936
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	21,734
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	49,580
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,597
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	17,504
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,309
Financing Receivable, Revolving	3,002
Financing Receivable, before Allowance for Credit Loss	108,662
Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	65,282
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	23,022
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	24,126
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	97,292
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	21,116
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	58,404
Financing Receivable, Revolving	71,568
Financing Receivable, before Allowance for Credit Loss	360,810
Substandard [Member] \| Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	17,246
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	21,985
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,076
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,675
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,578
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	13,390
Financing Receivable, Revolving	68,976
Financing Receivable, before Allowance for Credit Loss	132,926
Substandard [Member] \| Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,154
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	14,989
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	13,182
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss	29,325
Substandard [Member] \| Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	46,882
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,037
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,061
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	81,435
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	17,538
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	45,014
Financing Receivable, Revolving	2,592
Financing Receivable, before Allowance for Credit Loss	198,559
Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	13,097
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	189
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	6,807
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	391
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	502
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,743
Financing Receivable, Revolving	25
Financing Receivable, before Allowance for Credit Loss	24,754
Non-Accrual [Member] \| Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	12,619
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,327
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	391
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	502
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,659
Financing Receivable, Revolving	25
Financing Receivable, before Allowance for Credit Loss	22,524
Non-Accrual [Member] \| Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	478
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	188
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,480
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	84
Financing Receivable, Revolving	0
Financing Receivable, before Allowance for Credit Loss	$ 2,230

Loans And Allowance For Credit Losses (Credit Quality Indicators of the Commercial Loan Portfolio) (Details) - Commercial Portfolio Segment [Member]
$ in Thousands