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Loss And Loss Adjustment Expense Reserves (Summary Of Credit Impairments Related To Derivatives) (Narrative) (Detail) (USD $) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | Sep. 30, 2013 securityloan
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |
Discount rate of credit impairments | 5.09% |  |  |
Proprietary performance data on CRE loans, amount from 1992 to 2011 |  |  |  | 80,000
Additional estimated credit impairment on Cmbs derivatives | $ 601,000,000 |  |  |
Aggregate ITD credit impairment on Cmbs derivatives since 2010 | 4,200,000,000 |  |  |
Cmbs severities exceeded complete loss in certain instances | 100.00% |  |  |
Policyholder (Benefits) And Claims Incurred Net | 117,000,000 | 50,000,000 | (80,000,000) |
Commercial Real Estate Collateralized Debt Obligations [Member] |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | $ (33,000,000) |  |  |
Minimum [Member] |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |
Percentage of loss on liquidation | 1.00% |  |  |
Maximum [Member] |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |
Percentage of loss on liquidation | 2.00% |  |  |

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- Definition Additional Estimated Credit Impairment On Cmbs Derivatives + References No definition available. + Details
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- Definition Aggregate ITD Credit Impairment On Cmbs Derivatives + References No definition available. + Details
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- Details
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- Definition Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.5) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 5 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387 + Details
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