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	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Market Value	$ 1,324,821	$ 405,189
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(44,868)	(4,642)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	332,191	225,456
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(19,687)	(15,661)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	1,657,012	630,645
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(64,555)	(20,303)
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	17,315	5,875
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(1,273)	(24)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	31,679	19,291
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(4,132)	(2,833)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	48,994	25,166
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(5,405)	(2,857)
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	425,627	103,313
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(8,982)	(1,671)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	111,150	110,161
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(5,647)	(10,564)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	536,777	213,474
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(14,629)	(12,235)
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	312,341	57,225
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(10,408)	(678)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	14,865	16,385
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(663)	(1,008)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	327,206	73,610
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(11,071)	(1,686)
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	188,389	61,440
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(10,121)	(1,227)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	42,791	13,849
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(4,775)	(474)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	231,180	75,289
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	(14,896)	(1,701)
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
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation
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	381,149	177,336
Fixed maturity securities, Duration of Unrealized Loss, Less than 12 months, Gross Unrealized Depreciation	(14,084)	(1,042)
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Market Value	131,706	65,770
Fixed maturity securities, Duration of Unrealized Loss, Greater than 12 months, Gross Unrealized Depreciation	(4,470)	(782)
Fixed maturity securities, Duration of Unrealized Loss, Total, Market Value	512,855	243,106
Fixed maturity securities, Duration of Unrealized Loss, Total, Gross Unrealized Depreciation	$ (18,554)	$ (1,824)