| **Schedule V. Valuation and Qualifying Accounts** | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
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| **Valuation and Qualifying Accounts [Abstract]**  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Schedule V. Valuation and Qualifying Accounts     | SCHEDULE V. VALUATION AND QUALIFYING ACCOUNTS(In millions)Balance at Beginning of Period Charged to Costs and Expenses Charged to Other Accounts (a) Deductions Balance at End of PeriodYear ended December 31, 2011         Deducted from assets:         Allowance for doubtful accounts:         Insurance and reinsurance receivables$285 $(55) $— $(27) $203Year ended December 31, 2010         Deducted from assets:         Allowance for doubtful accounts:         Insurance and reinsurance receivables$553 $(232) $(1) $(35) $285Year ended December 31, 2009         Deducted from assets:         Allowance for doubtful accounts:         Insurance and reinsurance receivables$587 $4 $(1) $(37) $553(a)    Amount includes effects of foreign currency translation. |

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| - Definition
The entire disclosure for any allowance and reserve accounts (their beginning and ending balances, as well as a reconciliation by type of activity during the period). Alternatively, disclosure of the required information may be within the footnotes to the financial statements or a supplemental schedule to the financial statements.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e24092-122690
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