v2.3.0.15
Investments (Summary Of Gross Unrealized Investment Losses By Length Of Time That Securities Have Continuously Been In An Unrealized Loss Position) (Details) (USD $)
In Thousands
Sep. 30, 2011
Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months$ 325,526$ 1,161,448
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(31,135)(50,890)
Available-for-sale securities, Estimated Fair Value, 12 months or longer65,72153,923
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(3,989)(5,315)
Available-for-sale securities, Estimated Fair Value391,2471,215,371
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(35,124)(56,205)
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 months6,74723,574
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(12)(49)
Available-for-sale securities, Estimated Fair Value, 12 months or longer00
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer00
Available-for-sale securities, Estimated Fair Value6,74723,574
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(12)(49)
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 months2,736942,935
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(1)(27,463)
Available-for-sale securities, Estimated Fair Value, 12 months or longer43,02122,468
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(1,358)(1,987)
Available-for-sale securities, Estimated Fair Value45,757965,403
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(1,359)(29,450)
Foreign Governments [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months 119,211
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months (2,440)
Available-for-sale securities, Estimated Fair Value, 12 months or longer 4,955
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer (159)
Available-for-sale securities, Estimated Fair Value 124,166
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses (2,599)
Residential Mortgage-Backed Securities [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months3,89320,972
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(5,925)(10,822)
Available-for-sale securities, Estimated Fair Value, 12 months or longer2,24110,534
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(10)(2,694)
Available-for-sale securities, Estimated Fair Value6,13431,506
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(5,935)(13,516)
Asset-Backed Securities [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months121 
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(1) 
Available-for-sale securities, Estimated Fair Value, 12 months or longer35 
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(7) 
Available-for-sale securities, Estimated Fair Value156 
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(8) 
All Other Corporate Bonds [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months47,89315,294
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(7,554)(7,921)
Available-for-sale securities, Estimated Fair Value, 12 months or longer8,14115,966
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(1,492)(475)
Available-for-sale securities, Estimated Fair Value56,03431,260
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(9,046)(8,396)
Fixed Maturities [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months61,3901,121,986
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(13,493)(48,695)
Available-for-sale securities, Estimated Fair Value, 12 months or longer53,43853,923
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(2,867)(5,315)
Available-for-sale securities, Estimated Fair Value114,8281,175,909
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(16,360)(54,010)
Insurance Companies, Banks And Trusts [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months56,75522,750
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(9,050)(1,496)
Available-for-sale securities, Estimated Fair Value, 12 months or longer00
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer00
Available-for-sale securities, Estimated Fair Value56,75522,750
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(9,050)(1,496)
Industrial, Consumer And All Other [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months117,38216,712
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(8,591)(699)
Available-for-sale securities, Estimated Fair Value, 12 months or longer12,2830
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(1,122)0
Available-for-sale securities, Estimated Fair Value129,66516,712
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(9,713)(699)
Equity Securities [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months174,13739,462
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(17,641)(2,195)
Available-for-sale securities, Estimated Fair Value, 12 months or longer12,2830
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer(1,122)0
Available-for-sale securities, Estimated Fair Value186,42039,462
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses(18,763)(2,195)
Short-Term Investments [Member]
  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale securities, Estimated Fair Value, Less than 12 months89,999 
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, Less than 12 months(1) 
Available-for-sale securities, Estimated Fair Value, 12 months or longer0 
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses, 12 months or longer0 
Available-for-sale securities, Estimated Fair Value89,999 
Available-for-sale securities, Gross Unrealized Holding and Other-Than-Temporary Impairment Losses$ (1)