|
Fair Value Measurements (Balances Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $)
In Thousands, unless otherwise specified
|
Sep. 30, 2012
|
Dec. 31, 2011
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
$ 5,280,549 |
$ 5,538,174 |
| Total equity securities |
2,341,253 |
1,873,927 |
| Short-term investments |
729,042 |
541,014 |
| Derivative contracts |
15,600 |
29,300 |
|
Residential Mortgage-Backed Securities [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
278,343 |
|
|
Asset-Backed Securities [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
15,008 |
|
|
Fair Value, Measurements, Recurring [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
5,280,549 |
5,538,174 |
| Total equity securities |
2,341,253 |
1,873,927 |
| Short-term investments |
729,042 |
541,014 |
| Available-for-sale investments, estimated fair value |
8,350,844 |
7,953,115 |
| Derivative contracts |
15,650 |
29,331 |
|
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
| Total equity securities |
2,341,253 |
1,873,927 |
| Short-term investments |
650,472 |
477,348 |
| Available-for-sale investments, estimated fair value |
2,991,725 |
2,351,275 |
| Derivative contracts |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
5,280,549 |
5,538,174 |
| Total equity securities |
0 |
0 |
| Short-term investments |
78,570 |
63,666 |
| Available-for-sale investments, estimated fair value |
5,359,119 |
5,601,840 |
| Derivative contracts |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
| Total equity securities |
0 |
0 |
| Short-term investments |
0 |
0 |
| Available-for-sale investments, estimated fair value |
0 |
0 |
| Derivative contracts |
15,650 |
29,331 |
|
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
321,953 |
322,193 |
|
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
321,953 |
322,193 |
|
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
2,910,418 |
2,930,521 |
|
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
2,910,418 |
2,930,521 |
|
Fair Value, Measurements, Recurring [Member] | Obligations Of States, Municipalities And Political Subdivisions [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
602,216 |
616,814 |
|
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
602,216 |
616,814 |
|
Fair Value, Measurements, Recurring [Member] | Foreign Governments [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
278,343 |
389,184 |
|
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
278,343 |
389,184 |
|
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
15,008 |
16,818 |
|
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
15,008 |
16,818 |
|
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Public Utilities [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
61,653 |
69,427 |
|
Fair Value, Measurements, Recurring [Member] | Public Utilities [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Public Utilities [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
61,653 |
69,427 |
|
Fair Value, Measurements, Recurring [Member] | Public Utilities [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | All Other Corporate Bonds [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
1,090,958 |
1,193,217 |
|
Fair Value, Measurements, Recurring [Member] | All Other Corporate Bonds [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | All Other Corporate Bonds [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
1,090,958 |
1,193,217 |
|
Fair Value, Measurements, Recurring [Member] | All Other Corporate Bonds [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total fixed maturities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Insurance Companies, Banks And Trusts [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
823,718 |
684,703 |
|
Fair Value, Measurements, Recurring [Member] | Insurance Companies, Banks And Trusts [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
823,718 |
684,703 |
|
Fair Value, Measurements, Recurring [Member] | Insurance Companies, Banks And Trusts [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Insurance Companies, Banks And Trusts [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
1,517,535 |
1,189,224 |
|
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member] | Level 1 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
1,517,535 |
1,189,224 |
|
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member] | Level 2 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
0 |
0 |
|
Fair Value, Measurements, Recurring [Member] | Industrial, Consumer And All Other [Member] | Level 3 [Member]
|
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total equity securities |
$ 0 |
$ 0 |