Loans And Allowance For Loan Losses (Summary Of Activity In The Allowance For Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 159,532	$ 157,832	$ 159,532	$ 155,932
Provision	10,043	10,758	20,439	21,886
Loans charged off	13,685	13,946	27,416	26,822
Less recoveries on loans	3,642	3,188	6,977	6,836
Net loan charge-offs (recoveries)	10,043	10,758	20,439	19,986
Balance at end of period	159,532	157,832	159,532	157,832
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	93,065	92,951	93,704	91,361
Provision	485	(111)	(409)	1,002
Loans charged off	362	531	728	1,077
Less recoveries on loans	663	430	1,284	1,453
Net loan charge-offs (recoveries)	(301)	101	(556)	(376)
Balance at end of period	93,851	92,739	93,851	92,739
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	66,467	64,881	65,828	64,571
Provision	9,558	10,869	20,848	20,884
Loans charged off	13,323	13,415	26,688	25,745
Less recoveries on loans	2,979	2,758	5,693	5,383
Net loan charge-offs (recoveries)	10,344	10,657	20,995	20,362
Balance at end of period	$ 65,681	$ 65,093	$ 65,681	$ 65,093