Investments (Summary Of Gross Gains (Losses) From Sales Of Fixed Maturity And Equity Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales of securities	$ 94,027	$ 287,337	$ 237,444	$ 837,010
Gross gains from sales	3,679	3,316	12,667	17,582
Gross losses from sales	(1,427)	(8,729)	(3,707)	(36,820)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales of securities	52,340	37,000	291,880	116,792
Gross gains from sales	975	722	27,801	3,102
Gross losses from sales	$ (3,345)	$ (928)	$ (7,854)	$ (1,399)