Fair Value Measurements (Summary Of Changes In Fair Value Of Level 3 Financial Assets And Financial Liabilities Held At Fair Value) (Details) - Partnership Interest in a Private Credit Fund [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 1,481	$ 9,068
Net realized (losses) gains included in earnings	(36)	691
Purchases	0	1,481
Sales/settlements	0	(9,759)
Ending Balance	1,445	1,481
The amount of total (losses) gains for the period included in earnings attributable to assets still held at December 31	$ (36)	$ 0