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	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	$ 1,292,542	$ 1,324,834
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(19,164)	(44,870)
Fixed maturity securities, Greater than 12 months, Market Value	772,190	332,191
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(22,854)	(19,687)
Available-for-sale Securities, Market Value, Total	2,064,732	1,657,025
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(42,018)	(64,557)
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	1,292,542	1,324,821
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(19,164)	(44,868)
Fixed maturity securities, Greater than 12 months, Market Value	772,190	332,191
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(22,854)	(19,687)
Available-for-sale Securities, Market Value, Total	2,064,732	1,657,012
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(42,018)	(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	35,516	39,274
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(190)	(302)
Fixed maturity securities, Greater than 12 months, Market Value	24,483	8,751
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(625)	(644)
Available-for-sale Securities, Market Value, Total	59,999	48,025
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(815)	(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	18,198	92,760
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(426)	(4,852)
Fixed maturity securities, Greater than 12 months, Market Value	36,680	39,689
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(568)	(4,170)
Available-for-sale Securities, Market Value, Total	54,878	132,449
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(994)	(9,022)
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	925,037	388,721
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(16,140)	(8,981)
Fixed maturity securities, Greater than 12 months, Market Value	185,950	56,156
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(5,370)	(3,512)
Available-for-sale Securities, Market Value, Total	1,110,987	444,877
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(21,510)	(12,493)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	30,208
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(87)
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	30,208
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(87)
Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	10,365
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(1)
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	10,365
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(1)
Agency Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	35,576	381,149
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(108)	(14,084)
Fixed maturity securities, Greater than 12 months, Market Value	299,229	131,504
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(6,734)	(4,437)
Available-for-sale Securities, Market Value, Total	334,805	512,653
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(6,842)	(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	51,430	100,984
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(349)	(5,255)
Fixed maturity securities, Greater than 12 months, Market Value	76,092	29,174
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(3,925)	(2,686)
Available-for-sale Securities, Market Value, Total	127,522	130,158
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(4,274)	(7,941)
Foreign Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	186,212	321,933
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(1,863)	(11,394)
Fixed maturity securities, Greater than 12 months, Market Value	149,756	66,715
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(5,632)	(4,205)
Available-for-sale Securities, Market Value, Total	335,968	388,648
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(7,495)	(15,599)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value		13
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation		(2)
Available-for-sale Securities, Market Value, Total		13
Available-for-sale Securities, Gross Unrealized Depreciation, Total		$ (2)