|**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)201320122011Deferred acquisition costs$624$598Reserves for unpaid claim and claim adjustment expenses24,01524,696Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%)1,5861,850Unearned premiums3,7183,610Net written premiums7,3486,964$6,798Net earned premiums7,2716,8816,603Net investment income2,2402,0741,845Incurred claim and claim adjustment expenses related to current year5,1135,2664,901Incurred claim and claim adjustment expenses related to prior years(115)(180)(429)Amortization of deferred acquisition costs1,3621,2741,176Paid claim and claim adjustment expenses5,5665,2574,499
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|As of and for the years ended December 31                                                                                    | Consolidated Property and Casualty Operations                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|(In millions)                                                                                                                | 2013                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|Deferred acquisition costs                                                                                                   | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Reserves for unpaid claim and claim adjustment expenses                                                                      | 24,015                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%) | 1,586                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Unearned premiums                                                                                                            | 3,718                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Net written premiums                                                                                                         | 7,348                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Net earned premiums                                                                                                          | 7,271                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Net investment income                                                                                                        | 2,240                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Incurred claim and claim adjustment expenses related to current year                                                         | 5,113                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Incurred claim and claim adjustment expenses related to prior years                                                          | (115                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|Amortization of deferred acquisition costs                                                                                   | 1,362                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Paid claim and claim adjustment expenses                                                                                     | 5,566                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

X- DefinitionThe 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.+ ReferencesReference 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+ Details**Name:**
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