| **Property Casualty Loss And Loss Expenses (Tables)**         | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| **Insurance [Abstract]**                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Consolidated Property Casualty Loss And Loss Expense Reserves | This table summarizes activity for our consolidated property casualty loss and loss expense reserves:(In millions) Years ended December 31,  2013 2012 2011Gross loss and loss expense reserves, January 1 $4,169 $4,280 $4,137Less reinsurance receivable 356 375 326Net loss and loss expense reserves, January 1 3,813 3,905 3,811Net incurred loss and loss expenses related to:      Current accident year 2,448 2,533 2,620Prior accident years (147) (396) (285)Total incurred 2,301 2,137 2,335Net paid loss and loss expenses related to:      Current accident year 1,045 1,123 1,206Prior accident years 1,127 1,106 1,035Total paid 2,172 2,229 2,241       Net loss and loss expense reserves, December 31 3,942 3,813 3,905Plus reinsurance receivable 299 356 375Gross loss and loss expense reserves, December 31 $4,241 $4,169 $4,280        |

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Consolidated Property Casualty Loss And Loss Expense Reserves
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