v3.2.0.727
Investments (Summary Of Gross Unrealized Investment Losses By Length Of Time That Securities Have Continuously Been In An Unrealized Loss Position) (Details) - USD ($)
$ in Thousands
Jun. 30, 2015
Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months $ 1,724,505 $ 697,102
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (41,615) (13,139)
Available-for-sale securities, estimated fair value, 12 months or longer 906,844 1,333,930
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (22,198) (22,079)
Available-for-sale securities, estimated fair value 2,631,349 2,031,032
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (63,813) (35,218)
U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 97,844 108,250
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (2,842) (62)
Available-for-sale securities, estimated fair value, 12 months or longer 114,198 163,359
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (1,013) (2,101)
Available-for-sale securities, estimated fair value 212,042 271,609
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (3,855) (2,163)
Obligations Of States, Municipalities And Political Subdivisions [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 654,959 58,583
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (12,765) (542)
Available-for-sale securities, estimated fair value, 12 months or longer 63,885 92,441
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (4,265) (2,817)
Available-for-sale securities, estimated fair value 718,844 151,024
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (17,030) (3,359)
Foreign Governments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 31,312 18,856
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (542) (386)
Available-for-sale securities, estimated fair value, 12 months or longer 44,756 56,217
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (514) (655)
Available-for-sale securities, estimated fair value 76,068 75,073
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (1,056) (1,041)
Commercial Mortgage-Backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 124,536 45,931
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (703) (210)
Available-for-sale securities, estimated fair value, 12 months or longer 97,983 147,558
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (1,162) (2,392)
Available-for-sale securities, estimated fair value 222,519 193,489
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (1,865) (2,602)
Residential Mortgage-Backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 112,947 9,613
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (2,832) (2,285)
Available-for-sale securities, estimated fair value, 12 months or longer 156,760 207,374
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (3,699) (3,455)
Available-for-sale securities, estimated fair value 269,707 216,987
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (6,531) (5,740)
Asset-Backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 12,146 30,448
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (11) (20)
Available-for-sale securities, estimated fair value, 12 months or longer 46,122 45,160
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (499) (662)
Available-for-sale securities, estimated fair value 58,268 75,608
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (510) (682)
Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 433,329 141,176
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (9,696) (2,263)
Available-for-sale securities, estimated fair value, 12 months or longer 356,992 621,821
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (8,486) (9,997)
Available-for-sale securities, estimated fair value 790,321 762,997
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (18,182) (12,260)
Total Fixed Maturities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 1,467,073 412,857
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (29,391) (5,768)
Available-for-sale securities, estimated fair value, 12 months or longer 880,696 1,333,930
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (19,638) (22,079)
Available-for-sale securities, estimated fair value 2,347,769 1,746,787
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (49,029) (27,847)
Insurance, Banks And Other Financial Institutions [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 13,307 16,219
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (578) (1,531)
Available-for-sale securities, estimated fair value, 12 months or longer 8,040 0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (772) 0
Available-for-sale securities, estimated fair value 21,347 16,219
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (1,350) (1,531)
Industrial, Consumer And All Other [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 84,162 86,062
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (11,641) (5,834)
Available-for-sale securities, estimated fair value, 12 months or longer 18,108 0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (1,788) 0
Available-for-sale securities, estimated fair value 102,270 86,062
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (13,429) (5,834)
Total Equity Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 97,469 102,281
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (12,219) (7,365)
Available-for-sale securities, estimated fair value, 12 months or longer 26,148 0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer (2,560) 0
Available-for-sale securities, estimated fair value 123,617 102,281
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses (14,779) (7,365)
Short-Term Investments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, estimated fair value, less than 12 months 159,963 181,964
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, less than 12 months (5) (6)
Available-for-sale securities, estimated fair value, 12 months or longer 0 0
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses, 12 months or longer 0 0
Available-for-sale securities, estimated fair value 159,963 181,964
Available-for-sale securities, gross unrealized holding and other-than-temporary impairment losses $ (5) $ (6)