| **Accumulated Other Comprehensive Income**            | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
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| **Accumulated Other Comprehensive Income [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Comprehensive Income (Loss) Note                      | ACCUMULATED OTHER COMPREHENSIVE INCOME Accumulated other comprehensive income includes changes in unrealized gains and losses on available for sale investments and other invested assets, changes in pension obligations and changes in life deferred acquisition costs, life policy reserves and other as follows:    (In millions) Three months ended March 31,  2013  2012  Before tax Income tax Net  Before tax Income tax NetAccumulated unrealized gains, net, on investments available for sale, beginning of period $1,875 $647 $1,228  $1,489 $512 $977              Other comprehensive income before reclassification  397 139 258  241 84 157Reclassification adjustment for realized gains, net, included in net income (41) (15) (26)  (13) (4) (9)Effect on other comprehensive income 356 124 232  228 80 148Accumulated unrealized gains, net, on investments available for sale, end of period $2,231 $771 $1,460  $1,717 $592 $1,125              Accumulated unrealized losses, net, for pension obligations, beginning of period $(101) $(35) $(66)  $(88) $(31) $(57)Other comprehensive income before reclassification — — —  — — —Reclassification adjustment for amortization of actuarial loss and prior service cost, net, included in net income 2 1 1  2 1 1Effect on other comprehensive income 2 1 1  2 1 1Accumulated unrealized losses, net, for pension obligations, end of period $(99) $(34) $(65)  $(86) $(30) $(56)              Accumulated unrealized losses, net, on life deferred acquisition costs, life policy reserves and other, beginning of period $(50) $(17) $(33)  $(29) $(10) $(19)Effect on other comprehensive income — — —  (5) (2) (3)Accumulated unrealized  losses, net, on life deferred acquisition costs, life policy reserves and other, end of period $(50) $(17) $(33)  $(34) $(12) $(22)              Accumulated other comprehensive income, beginning of period $1,724 $595 $1,129  $1,372 $471 $901Change in unrealized gains, net, on investments available for sale  356 124 232  228 80 148Change in pension obligations 2 1 1  2 1 1Change in life deferred acquisition costs, life policy reserves and other — — —  (5) (2) (3)Effect on other comprehensive income 358 125 233  225 79 146Accumulated other comprehensive income, end of period $2,082 $720 $1,362  $1,597 $550 $1,047The reclassification adjustment for realized gains on investments available for sale are recorded in the total realized investment gains, net, line item of the condensed consolidated statements of income. The reclassification adjustment for amortization of actuarial loss and prior service cost, net, are recorded in the insurance losses and policyholder benefits, underwriting, acquisition and insurance expenses and the other operating expenses line items of the condensed consolidated statements of income. There was no reclassification adjustment for losses on life deferred acquisition, life policy reserves and other for the periods ending March 31, 2013 and 2012. |

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| - Definition
The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e640-108580Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14-26 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Reclassification Adjustments -URI http://asc.fasb.org/extlink&oid=6522872Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e681-108580Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e709-108580Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669619-108580Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e689-108580Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e716-108580
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