Investments (Summary Of Components Of Net Investment Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	$ 313,132	$ 319,341	$ 326,794
Funds held interest income (expense)	6,925	4,408	(1,131)
Gross investment income	320,057	323,749	325,663
Investment expenses	(23,061)	(17,604)	(12,730)
Net investment income	296,996	306,145	312,933
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	210,416	216,796	232,287
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	36,274	39,284	29,694
Short Term Investments And Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	1,090	1,051	1,078
Limited Partnerships [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	36,737	39,696	42,349
Dividends From Parent's Shares [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	21,287	18,663	18,645
Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	$ 7,328	$ 3,851	$ 2,741