Loans And Allowance For Loan Losses (Summary Of Activity In The Allowance For Loan Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 159,532	$ 155,932	$ 151,532
Provision for loan losses	42,694	45,244	36,318
Loans charged off	55,821	55,179	50,978
Less recoveries	13,527	13,535	19,060
Net loans charged-off (recoveries)	42,294	41,644	31,918
Balance at end of period	159,932	159,532	155,932
Commercial Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	93,704	91,361	82,086
Provision for loan losses	254	2,327	4,898
Loans charged off	3,164	2,538	3,258
Less recoveries	2,075	2,554	7,635
Net loans charged-off (recoveries)	1,089	(16)	(4,377)
Balance at end of period	92,869	93,704	91,361
Personal Banking Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	65,828	64,571	69,446
Provision for loan losses	42,440	42,917	31,420
Loans charged off	52,657	52,641	47,720
Less recoveries	11,452	10,981	11,425
Net loans charged-off (recoveries)	41,205	41,660	36,295
Balance at end of period	$ 67,063	$ 65,828	$ 64,571