|
Investments (Available-For-Sale Investments) (Details) (USD $)
In Thousands, unless otherwise specified
|
Sep. 30, 2012
|
Dec. 31, 2011
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
$ 6,937,684 |
$ 6,870,260 |
| Available-for-sale investments, gross unrealized holding gains |
1,430,691 |
1,100,525 |
| Available-for-sale investments, gross unrealized holding losses |
(8,482) |
(8,798) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
(9,049) |
(8,872) |
| Available-for-sale investments, estimated fair value |
8,350,844 |
7,953,115 |
|
U.S. Treasury Securities And Obligations Of U.S. Government Agencies [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
300,491 |
299,413 |
| Available-for-sale investments, gross unrealized holding gains |
21,462 |
22,789 |
| Available-for-sale investments, gross unrealized holding losses |
0 |
(9) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
321,953 |
322,193 |
|
Obligations Of States, Municipalities And Political Subdivisions [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
2,653,298 |
2,729,838 |
| Available-for-sale investments, gross unrealized holding gains |
257,461 |
201,477 |
| Available-for-sale investments, gross unrealized holding losses |
(341) |
(794) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
2,910,418 |
2,930,521 |
|
Foreign Governments [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
544,544 |
572,253 |
| Available-for-sale investments, gross unrealized holding gains |
57,673 |
45,629 |
| Available-for-sale investments, gross unrealized holding losses |
(1) |
(1,068) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
602,216 |
616,814 |
|
Residential Mortgage-Backed Securities [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
261,089 |
366,859 |
| Available-for-sale investments, gross unrealized holding gains |
19,515 |
24,601 |
| Available-for-sale investments, gross unrealized holding losses |
(3) |
(18) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
(2,258) |
(2,258) |
| Available-for-sale investments, estimated fair value |
278,343 |
389,184 |
|
Asset-Backed Securities [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
14,332 |
16,096 |
| Available-for-sale investments, gross unrealized holding gains |
676 |
731 |
| Available-for-sale investments, gross unrealized holding losses |
0 |
(9) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
15,008 |
16,818 |
|
Public Utilities [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
56,432 |
63,965 |
| Available-for-sale investments, gross unrealized holding gains |
5,221 |
5,462 |
| Available-for-sale investments, gross unrealized holding losses |
0 |
0 |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
61,653 |
69,427 |
|
All Other Corporate Bonds [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
1,003,063 |
1,124,528 |
| Available-for-sale investments, gross unrealized holding gains |
94,765 |
78,053 |
| Available-for-sale investments, gross unrealized holding losses |
(79) |
(2,750) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
(6,791) |
(6,614) |
| Available-for-sale investments, estimated fair value |
1,090,958 |
1,193,217 |
|
Total Fixed Maturities [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
4,833,249 |
5,172,952 |
| Available-for-sale investments, gross unrealized holding gains |
456,773 |
378,742 |
| Available-for-sale investments, gross unrealized holding losses |
(424) |
(4,648) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
(9,049) |
(8,872) |
| Available-for-sale investments, estimated fair value |
5,280,549 |
5,538,174 |
|
Insurance Companies, Banks And Trusts [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
442,119 |
389,421 |
| Available-for-sale investments, gross unrealized holding gains |
383,397 |
296,648 |
| Available-for-sale investments, gross unrealized holding losses |
(1,798) |
(1,366) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
823,718 |
684,703 |
|
Industrial, Consumer And All Other [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
933,287 |
766,873 |
| Available-for-sale investments, gross unrealized holding gains |
590,506 |
425,131 |
| Available-for-sale investments, gross unrealized holding losses |
(6,258) |
(2,780) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
1,517,535 |
1,189,224 |
|
Total Equity Securities [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
1,375,406 |
1,156,294 |
| Available-for-sale investments, gross unrealized holding gains |
973,903 |
721,779 |
| Available-for-sale investments, gross unrealized holding losses |
(8,056) |
(4,146) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
2,341,253 |
1,873,927 |
|
Short-Term Investments [Member]
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Available-for-sale investments, amortized cost |
729,029 |
541,014 |
| Available-for-sale investments, gross unrealized holding gains |
15 |
4 |
| Available-for-sale investments, gross unrealized holding losses |
(2) |
(4) |
| Available-for-sale investments, unrealized other-than-temporary impairment losses |
0 |
0 |
| Available-for-sale investments, estimated fair value |
$ 729,042 |
$ 541,014 |