Investments (Summary Of Components Of Net Investment Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	$ 73,875	$ 85,409	$ 140,301	$ 165,639
Funds held interest income (expense)	1,183	1,018	3,292	3,436
Gross investment income	75,058	86,427	143,593	169,075
Investment expenses	(6,422)	(4,691)	(11,170)	(10,470)
Net investment income	68,636	81,736	132,423	158,605
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	53,921	53,366	105,000	107,265
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	9,180	11,114	18,117	18,845
Short-Term Investments And Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	459	137	645	403
Limited Partnerships [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	2,695	14,192	(392)	25,540
Dividends From Parent's Shares [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	7,290	4,665	14,580	9,331
Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustment	$ 330	$ 1,935	$ 2,351	$ 4,255