Investments (Summary Of Gross Gains (Losses) From Sales Of Fixed Maturity And Equity Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales of securities	$ 402,528	$ 271,025	$ 1,392,801	$ 2,591,938
Gross gains from sales	18,721	14,270	54,077	42,316
Gross losses from sales	(15,291)	(8,980)	(55,104)	(25,300)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales of securities	116,565	35,924	329,750	185,157
Gross gains from sales	9,512	1,035	30,268	9,286
Gross losses from sales	$ (10,829)	$ (2,227)	$ (42,910)	$ (6,745)