Investments (Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Security Type) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	$ 621,262	$ 1,324,834
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(5,022)	(44,870)
Fixed maturity securities, Greater than 12 months, Market Value	798,094	332,191
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(21,093)	(19,687)
Available-for-sale Securities, Market Value, Total	1,419,356	1,657,025
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(26,115)	(64,557)
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	621,247	1,324,821
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(5,022)	(44,868)
Fixed maturity securities, Greater than 12 months, Market Value	798,094	332,191
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(21,093)	(19,687)
Available-for-sale Securities, Market Value, Total	1,419,341	1,657,012
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(26,115)	(64,555)
U.S. Treasury Securities And Obligations Of U.S. Government Agencies And Corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	105,986	39,274
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(45)	(302)
Fixed maturity securities, Greater than 12 months, Market Value	24,597	8,751
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(590)	(644)
Available-for-sale Securities, Market Value, Total	130,583	48,025
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(635)	(946)
Obligation Of U.S. States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value		92,760
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation		(4,852)
Fixed maturity securities, Greater than 12 months, Market Value	92,739	39,689
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(2,050)	(4,170)
Available-for-sale Securities, Market Value, Total	92,739	132,449
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(2,050)	(9,022)
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	345,912	388,721
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(2,814)	(8,981)
Fixed maturity securities, Greater than 12 months, Market Value	190,310	56,156
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(4,567)	(3,512)
Available-for-sale Securities, Market Value, Total	536,222	444,877
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(7,381)	(12,493)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	12,591
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(7)
Fixed maturity securities, Greater than 12 months, Market Value
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation
Available-for-sale Securities, Market Value, Total	12,591
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(7)
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation
Fixed maturity securities, Greater than 12 months, Market Value
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation
Available-for-sale Securities, Market Value, Total
Available-for-sale Securities, Gross Unrealized Depreciation, Total
Agency Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	56,079	381,149
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(235)	(14,084)
Fixed maturity securities, Greater than 12 months, Market Value	286,429	131,504
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(6,158)	(4,437)
Available-for-sale Securities, Market Value, Total	342,508	512,653
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(6,393)	(18,521)
Non-Agency Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Greater than 12 months, Market Value		202
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation		(33)
Available-for-sale Securities, Market Value, Total		202
Available-for-sale Securities, Gross Unrealized Depreciation, Total		(33)
Foreign Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	32,337	100,984
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(711)	(5,255)
Fixed maturity securities, Greater than 12 months, Market Value	65,825	29,174
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(3,227)	(2,686)
Available-for-sale Securities, Market Value, Total	98,162	130,158
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(3,938)	(7,941)
Foreign Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	68,342	321,933
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(1,210)	(11,394)
Fixed maturity securities, Greater than 12 months, Market Value	138,194	66,715
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(4,501)	(4,205)
Available-for-sale Securities, Market Value, Total	206,536	388,648
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(5,711)	(15,599)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	15	13
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation		(2)
Available-for-sale Securities, Market Value, Total	15	13
Available-for-sale Securities, Gross Unrealized Depreciation, Total		$ (2)