Allowance for Loan and Lease Loss and Credit Quality (Summary Of Reserve For Unfunded Commitments Activity) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reserve for Unfunded Commitments [Roll Forward]
Balance, beginning of period	$ 3,816	$ 3,531	$ 3,611	$ 3,574
Net charge to other expense	116	5	321	(38)
Balance, end of period	3,932	3,536	3,932	3,536
Unfunded loan commitments	$ 4,839,882	$ 4,118,259	$ 4,839,882	$ 4,118,259