Allowance for Loan and Lease Loss and Credit Quality (Summary Of Reserve For Unfunded Commitments Activity) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reserve for Unfunded Commitments [Roll Forward]
Balance, beginning of period	$ 3,963	$ 3,611
Net charge to other expense	166	(116)
Balance, end of period	4,129	3,495
Unfunded loan and lease commitments	$ 5,085,021	$ 4,215,048