| **Investments (Investment Income Realized Investment Gains And Losses And Change In Unrealized Investment Gains And Losses) (Details) (USD $)In Millions, unless otherwise specified** | 12 Months Ended |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| **Investment income summarized by investment category:**                                                                                                                               |            |   |   |
| Interest on fixed maturities                                                                                                                                                           | $ 413           | $ 420 | $ 424 |
| Dividends on equity securities                                                                                                                                                         | 122             | 115 | 104 |
| Other investment income                                                                                                                                                                | 3               | 3 | 4 |
| Total                                                                                                                                                                                  | 538             | 538 | 532 |
| Less investment expenses                                                                                                                                                               | 9               | 7 | 7 |
| Total                                                                                                                                                                                  | 529             | 531 | 525 |
| **Realized investment gains and losses summary:**                                                                                                                                      |            |   |   |
| Other                                                                                                                                                                                  | (7)             | 7 | 3 |
| Realized gains on investments                                                                                                                                                          | 83              | 42 | 70 |
| **Change in unrealized investment gains and losses and other summary:**                                                                                                                |            |   |   |
| Adjustment to deferred acquisition costs and life policy reserves                                                                                                                      | 41              | (28) | (14) |
| Pension obligations                                                                                                                                                                    | (83)            | 13 | 25 |
| Other                                                                                                                                                                                  | (7)             | 7 | 3 |
| Income taxes on above                                                                                                                                                                  | 202             | 124 | 71 |
| Other Comprehensive Income (Loss), Net of Tax                                                                                                                                          | 375             | 228 | 132 |
| Fixed Maturities [Member]                                                                                                                                                              |            |   |   |
| **Realized investment gains and losses summary:**                                                                                                                                      |            |   |   |
| Gross realized gains                                                                                                                                                                   | 12              | 35 | 11 |
| Gross realized losses                                                                                                                                                                  | 0               | 0 | 0 |
| Other-than-temporary impairments                                                                                                                                                       | 2               | 1 | 5 |
| **Change in unrealized investment gains and losses and other summary:**                                                                                                                |            |   |   |
| Unrealized gains on investments available-for-sale                                                                                                                                     | (387)           | 176 | 200 |
| Equity Securities [Member]                                                                                                                                                             |            |   |   |
| **Realized investment gains and losses summary:**                                                                                                                                      |            |   |   |
| Securities with embedded derivatives                                                                                                                                                   | 3               | 1 | (1) |
| Other                                                                                                                                                                                  | 6               | 2 | 6 |
| Gross realized gains                                                                                                                                                                   | 64              | 39 | 151 |
| Gross realized losses                                                                                                                                                                  | 0               | (2) | (40) |
| Other-than-temporary impairments                                                                                                                                                       | 0               | 32 | 52 |
| **Change in unrealized investment gains and losses and other summary:**                                                                                                                |            |   |   |
| Other                                                                                                                                                                                  | 6               | 2 | 6 |
| Unrealized gains on investments available-for-sale                                                                                                                                     | $ 847           | $ 210 | $ 39 |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Income derived from investments in debt and equity securities, cash and cash equivalents, and other long-term investments. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Other income represents all other investment income not including interest and dividends.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                            |
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| - Definition
Income derived from those other than interest and dividends.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Other Comprehensive Income, Unrealized gains losses on deferred acquisition costs , Period Increase (Decrease)
+ References
No definition available.
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| - Definition
Condensed Consolidated Statements of Comprehensive Operations (USD $) In Millions, except Per Share data, unless otherwise specified 3 Months Ended 9 Months Ended Sep. 30, 2012 Sep. 30, 2011 Sep. 30, 2012 Sep. 30, 2011 REVENUES Earned premiums $ 889 $ 812 $ 2,605 $ 2,367 Investment income, net of expenses 132 130 395 393 Total realized investment gains (losses), net 10 (2) 29 77 Fee revenues 1 1 4 3 Other revenues 3 3 8 8 Total revenues 1,035 944 3,041 2,848 BENEFITS AND EXPENSES Insurance losses and policyholder benefits 571 656 1,840 2,032 Underwriting, acquisition and insurance expenses 296 260 857 775 Interest expense 14 13 41 40 Other operating expenses 2 4 10 14 Total benefits and expenses 883 933 2,748 2,861 INCOME (LOSS) BEFORE INCOME TAXES 152 11 293 (13) PROVISION (BENEFIT) FOR INCOME TAXES Current 34 17 60 (9) Deferred 7 (25) 4 (34) Provision (benefit) for income taxes 41 (8) 64 (43) NET INCOMEX - DefinitionThe portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 19 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.22) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Other Comprehensive Income -URI http://asc.fasb.org/extlink&oid=6519514 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.18) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 10, 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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| - Definition
This item represents realized investment gains (losses) included in earnings for the period excluding those relating to other than temporary impairment losses on investments in debt securities. Includes realized investment gains and losses generated from the sale of debt securities, equity securities, investments in joint ventures and limited partnerships and from other than temporary impairments on investments other than debt securities. Also includes realized investment gains and losses are generated from prepayment premiums, recoveries of principal on previously impaired securities, provisions for losses on commercial mortgage and other loans, and fair value changes on embedded derivatives and derivatives that do not qualify for hedge accounting treatment, except those derivatives used in the Company's capacity as a broker or dealer.
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Other Than Temporary Impairment Losses
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| - Definition
This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.
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| - Definition
This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.
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| - Definition
Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.
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| - Definition
Amount of dividend income on nonoperating securities.
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| - Definition
Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.
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| - Definition
Amount of expenses related to the generation of investment income.
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| - Definition
Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.
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| - Definition
Amount after tax and reclassification adjustments of other comprehensive income (loss).
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| - Definition
Amount of tax expense (benefit) allocated to other comprehensive income (loss).
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.
+ References
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| - Definition
The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.
+ References
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