Investments (Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities By Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	$ 235,234	$ 595,297
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(2,647)	(13,710)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	268,438	249,785
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(19,500)	(21,758)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	503,672	845,082
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(22,147)	(35,468)
Due In One Year Or Less [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	12,962	9,583
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(287)	(59)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	35,341	26,204
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(5,663)	(4,486)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	48,303	35,787
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(5,950)	(4,545)
Due In One Year Through Five Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	116,020	213,809
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(1,805)	(4,754)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	149,214	137,972
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(11,175)	(9,576)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	265,234	351,781
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(12,980)	(14,330)
Due In Five Years Through Ten Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	29,938	186,061
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(175)	(5,484)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	45,936	37,964
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(1,587)	(2,391)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	75,874	224,025
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(1,762)	(7,875)
Due After Ten Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	1,976	23,741
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(26)	(446)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	14,136	19,753
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(459)	(4,918)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	16,112	43,494
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(485)	(5,364)
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value		819
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation		(6)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value		819
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation		(6)
Collateralized Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	74,338	161,284
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(354)	(2,961)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	23,811	27,892
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(616)	(387)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	98,149	189,176
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	$ (970)	$ (3,348)