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Loss And Loss Adjustment Expense Reserves (Loss And LAE Activity) (Narrative) (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Dec. 31, 2014
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | $ 39 | $ 20 | $ 79 | $ 82 |
Weighted average risk-free rate used to discount claim liability | 1.56% |  |  |  |
Insurance loss recoverable | $ 437 |  | 437 |  | $ 533
CDO Portfolio [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | 5 |  | 39 |  |
CDO Portfolio [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Elimination Of Loss And LAE Expense (Benefit) As Result Of Consolidating VIEs | 14 |  | 1 |  |
Second Lien Residential Mortgage Backed Securities And Reserves [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | 24 | 16 | 52 | 88 |
First Lien Residential Mortgage Backed Securities [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | 18 | 12 | 2 | 39 |
Financial Guarantee [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Aggregate CDO Loss And LAE Reserves | 149 |  | 149 |  | 111
Financial Guarantee [Member] | CDO Portfolio [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Elimination Of Loss And Lae Reserves As Result Of Consolidating VIEs | 226 |  | 226 |  | 225
Loss And Lae Reserves [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Reserves for expected future claim payments | 700 |  | 700 |  | 653
Expected recoveries of future payments | 220 |  | 220 |  | 147
Recoveries On Unpaid Losses [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Expected recoveries of future payments | 220 |  | 220 |  | 147
Insurance Loss Recoverable [Member] | Classified [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Insurance claim loss recoverable | 437 |  | 437 |  | 533
Insurance loss recoverable | 437 |  | 437 |  | 533
Loan Repurchase Commitments [Member] | Second Lien Residential Mortgage Backed Securities And Reserves [Member] | Ineligible Loan Recoveries [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Total estimated insurance recoveries | 394 |  | 394 |  | $ 379
Remedial Actions For Insured Obligations [Member] |  |  |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | $ 5 | $ 3 | $ 10 | $ 37 |

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- Definition Carrying amount as of the balance sheet date of paid insurance policy claims and LAE expense expected to be recovered. + References No definition available. + Details
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- Definition Carrying amount as of the balance sheet date of amounts expected to be recovered under the terms of insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 + Details
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- Definition This element represents the weighted average risk free rate used to discount the claim liability related to financial guarantee insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 9 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6933314&loc=SL5749324-161292 + 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 FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 5 -Article 7 + Details
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