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, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 160,682	$ 159,532	$ 159,932	$ 159,532
Provision	11,806	10,043	24,269	20,439
Loans charged off	14,458	13,685	29,189	27,416
Less recoveries on loans	3,152	3,642	6,170	6,977
Net loan charge-offs (recoveries)	11,306	10,043	23,019	20,439
Balance at end of period	161,182	159,532	161,182	159,532
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	93,643	93,065	92,869	93,704
Provision	(1,666)	485	(498)	(409)
Loans charged off	419	362	946	728
Less recoveries on loans	250	663	383	1,284
Net loan charge-offs (recoveries)	169	(301)	563	(556)
Balance at end of period	91,808	93,851	91,808	93,851
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	67,039	66,467	67,063	65,828
Provision	13,472	9,558	24,767	20,848
Loans charged off	14,039	13,323	28,243	26,688
Less recoveries on loans	2,902	2,979	5,787	5,693
Net loan charge-offs (recoveries)	11,137	10,344	22,456	20,995
Balance at end of period	$ 69,374	$ 65,681	$ 69,374	$ 65,681