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, 2019	Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 1,445	$ 1,481
Net realized gains (losses) included in earnings	101	(36)
Settlements	(343)	0
Ending Balance	1,203	1,445
The amount of total gains (losses) for the period included in earnings attributable to assets still held at December 31	$ 93	$ (36)