| **Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations** | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
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| **Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]**           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations     | SCHEDULE VI.  SUPPLEMENTAL INFORMATION CONCERNING PROPERTY AND CASUALTY INSURANCE OPERATIONSAs of and for the years ended December 31Consolidated Property and Casualty Operations(In millions)2012 2011 2010Deferred acquisition costs$598 $552 Reserves for unpaid claim and claim adjustment expenses24,696 24,228 Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%)1,850 1,569 Unearned premiums3,610 3,250 Net written premiums6,964 6,798 $6,471Net earned premiums6,881 6,603 6,514Net investment income2,074 1,845 2,097Incurred claim and claim adjustment expenses related to current year5,266 4,901 4,737Incurred claim and claim adjustment expenses related to prior years(180) (429) (545)Amortization of deferred acquisition costs1,274 1,176 1,168Paid claim and claim adjustment expenses5,257 4,499 4,667 |

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| - Definition
The entire disclosure for the supplemental schedule of information for an entity who has a consolidated property-casualty insurance underwriter, unconsolidated property-casualty subsidiary or fifty percent-or-less owned property-casualty equity investee.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12
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