Allowance for Loan and Lease Loss and Credit Quality (Summary Of Reserve For Unfunded Commitments Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reserve for Unfunded Commitments [Roll Forward]
Balance, beginning of period	$ 3,611	$ 3,574
Net charge to other expense	352	37
Balance, end of period	3,963	3,611
Unfunded loan commitments	$ 4,947,750	$ 4,192,059