Investments (Summary Of Changes In Net Unrealized Appreciation (Depreciation) For The Company's Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	$ (194,035)	$ 20,312
Deferred tax benefit (expense)	16,979	(1,623)
Deferred tax benefit (expense), other-than-temporary impairment	(3,383)	3,407
Total URA(D) on securities arising during the period	(180,439)	22,096	$ (402,774)
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	(197,231)	34,245
Fixed Maturity Securities, Other-Than-Temporary Impairment [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	8,411	(10,078)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	$ (5,215)	$ (3,855)