Loans And Allowance For Credit Losses (Summary of Activity in the Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 240,744	$ 240,744	$ 171,653	$ 139,643
Financing Receivable, Credit Loss, Expense (Reversal)	77,491	120,359
Financing Receivable, Allowance for Credit Loss, Writeoff	11,245	25,637
Financing Receivable, Allowance for Credit Loss, Recovery	2,845	6,379
Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery, Total	8,400	19,258
Off-Balance Sheet, Credit Loss, Liability	35,299	35,299	32,250	17,165	$ 1,075
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	3,049	18,134
Financing Receivable, Allowance for Credit Loss and Unfunded Lending Commitments, Total	276,043	276,043
Previously Reported [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss			171,653		160,682
Off-Balance Sheet, Credit Loss, Liability			32,250		1,075
Revision of Prior Period, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss			0	(21,039)
Off-Balance Sheet, Credit Loss, Liability			0	16,090
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	130,553	130,553	83,551	62,049
Financing Receivable, Credit Loss, Expense (Reversal)	50,245	71,353
Financing Receivable, Allowance for Credit Loss, Writeoff	3,386	3,802
Financing Receivable, Allowance for Credit Loss, Recovery	143	953
Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery, Total	3,243	2,849
Off-Balance Sheet, Credit Loss, Liability	34,052	34,052	31,061	16,456
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	2,991	17,596
Financing Receivable, Allowance for Credit Loss and Unfunded Lending Commitments, Total	164,605	164,605
Commercial Portfolio Segment [Member] | Previously Reported [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss			83,551		91,760
Off-Balance Sheet, Credit Loss, Liability			31,061		399
Commercial Portfolio Segment [Member] | Revision of Prior Period, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss			0	(29,711)
Off-Balance Sheet, Credit Loss, Liability			0	16,057
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	110,191	110,191	88,102	77,594
Financing Receivable, Credit Loss, Expense (Reversal)	27,246	49,006
Financing Receivable, Allowance for Credit Loss, Writeoff	7,859	21,835
Financing Receivable, Allowance for Credit Loss, Recovery	2,702	5,426
Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery, Total	5,157	16,409
Off-Balance Sheet, Credit Loss, Liability	1,247	1,247	1,189	709
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	58	538
Financing Receivable, Allowance for Credit Loss and Unfunded Lending Commitments, Total	$ 111,438	$ 111,438
Personal Banking Portfolio Segment [Member] | Previously Reported [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss			88,102		68,922
Off-Balance Sheet, Credit Loss, Liability			1,189		$ 676
Personal Banking Portfolio Segment [Member] | Revision of Prior Period, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss			0	8,672
Off-Balance Sheet, Credit Loss, Liability			$ 0	$ 33