Derivative Financial Instruments (Schedule Of Derivative Gains And Losses In The Consolidated Statements Of Operations) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Financial Instruments [Line Items]
(Losses) Gains Recognized in Income	$ 154	$ 15,379	$ (3,357)
Total Return Swap [Member] | Net realized investment gains [Member]
Derivative Financial Instruments [Line Items]
(Losses) Gains Recognized in Income	(2,137)	11,533	(6,438)
Equity contracts [Member] | Net realized investment gains [Member]
Derivative Financial Instruments [Line Items]
(Losses) Gains Recognized in Income	$ 2,291	$ 3,846	$ 3,081