Loans And Allowance For Credit Losses (Summary Of Activity In The Allowance For Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at start of period	$ 161,182	$ 159,932
Provision	10,963	35,232
Loans charged off	14,480	43,669
Less recoveries on loans	3,017	9,187
Allowance for Loan and Lease Losses Write-offs, Net, Total	11,463	34,482
Balance at end of period	160,682	160,682
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at start of period	91,808	92,869
Provision	553	55
Loans charged off	490	1,436
Less recoveries on loans	199	582
Allowance for Loan and Lease Losses Write-offs, Net, Total	291	854
Balance at end of period	92,070	92,070
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance at start of period	69,374	67,063
Provision	10,410	35,177
Loans charged off	13,990	42,233
Less recoveries on loans	2,818	8,605
Allowance for Loan and Lease Losses Write-offs, Net, Total	11,172	33,628
Balance at end of period	$ 68,612	$ 68,612