Investments (Summary Of Changes In Net Unrealized Appreciation (Depreciation) For The Company's Investments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	$ 70,023	$ 60,946
Deferred tax benefit (expense)	(24,439)	(17,924)
Deferred tax benefit (expense), other-than-temporary impairment	(69)	(3,407)
Total URA(D) on securities arising during the period	45,515	39,615
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	69,826	51,211
Fixed Maturity Securities, Other-Than-Temporary Impairment [Member]
Schedule of Available-for-sale Securities [Line Items]
Change in unrealized appreciation (depreciation), pre-tax	$ 197	$ 9,735