Residential Mortgage Servicing Rights (Schedule Of Information Relates To Serviced Loan Portfolio) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Transfers and Servicing [Abstract]
Balance of loans serviced for others	$ 13,026,720	$ 12,276,943	$ 15,978,885
MSR as a percentage of serviced loans	0.71%	0.94%	1.06%