Residential Mortgage Servicing Rights (Schedule Of Information Relates To Serviced Loan Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Transfers and Servicing [Abstract]
Balance of loans serviced for others	$ 15,902,587	$ 15,978,885
MSR as a percentage of serviced loans	1.00%	1.06%