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, 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)
Due In One Year Or Less [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	8,185	17,315
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(37)	(1,273)
Fixed maturity securities, Greater than 12 months, Market Value	69,568	31,679
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(5,163)	(4,132)
Available-for-sale Securities, Market Value, Total	77,753	48,994
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(5,200)	(5,405)
Due In One Year Through Five Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	714,621	425,627
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(10,537)	(8,982)
Fixed maturity securities, Greater than 12 months, Market Value	274,095	111,150
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(7,104)	(5,647)
Available-for-sale Securities, Market Value, Total	988,716	536,777
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(17,641)	(14,629)
Due In Five Years Through Ten Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	464,811	312,341
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(7,784)	(10,408)
Fixed maturity securities, Greater than 12 months, Market Value	85,723	14,865
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(2,579)	(663)
Available-for-sale Securities, Market Value, Total	550,534	327,206
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(10,363)	(11,071)
Due After Ten Years [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	28,776	188,389
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(610)	(10,121)
Fixed maturity securities, Greater than 12 months, Market Value	43,575	42,791
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(1,274)	(4,775)
Available-for-sale Securities, Market Value, Total	72,351	231,180
Available-for-sale Securities, Gross Unrealized Depreciation, Total	(1,884)	(14,896)
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)
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fixed maturity securities, Less than 12 months, Market Value	45,941	381,149
Fixed maturity securities, Less than 12 months, Gross Unrealized Depreciation	(109)	(14,084)
Fixed maturity securities, Greater than 12 months, Market Value	299,229	131,706
Fixed maturity securities, Greater than 12 months, Gross Unrealized Depreciation	(6,734)	(4,470)
Available-for-sale Securities, Market Value, Total	345,170	512,855
Available-for-sale Securities, Gross Unrealized Depreciation, Total	$ (6,843)	$ (18,554)