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Loss And Loss Adjustment Expense Reserves (RMBS Recoveries) (Narrative) (Details) (USD $) | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2010 | Jun. 30, 2011 | Dec. 31, 2010
Estimated insurance recoveries, after income taxes | $ 1,600,000,000 | $ 1,800,000,000 | $ 1,600,000,000
Income tax rate calculated |  | 35.00% |
Percentage of ineligible mortgage loans |  | 80.00% |
Percentage of recognized estimated recoveries in relationship to consolidated total shareholder's equity |  | 95.00% | 58.00%
Percentage of statutory measures |  | 60.00% | 59.00%
Contract Claims On Ineligble Mortgages |  | 4,600,000,000 |
Settlement received for assured guaranty put-back claims |  | 1,100,000,000 |
Repurchase request resolved | 8,000,000,000 |  |
Aggregate of estimated potential recoveries |  | 2,700,000,000 |
Reviewed [Member] | RMBS [Member] |  |  |
Number of mortgage loans reviewed |  | 50,000 |
RMBS [Member] |  |  |
Estimated insurance recoveries |  | 2,700,000,000 |
Insurance loss recoverable |  | 1,800,000,000 |
Loan repurchase commitments |  | $ 905,000,000 |
Number of individual mortgages within securitizations, minimum |  | 500,000 |
Number of insured issues reviewed |  | 32 |
Breach rate percentage |  | 80.00% |
Sum of probabilities assigned to all scenarios |  | 100.00% |
Current risk-free rate associated with underlying transaction, range, minimum |  | 1.32% |
Current risk-free rate associated with underlying transaction, range, maximum |  | 3.14% |

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- Definition The fair value of financial instruments that represent the right of the Trust against the seller/servicer for loans that were not compliant with the representations and warranties of the loan underwriting. The Trust has the right to demand that the transferor replace ineligible loans with a compliant loan or repurchase the non-compliant loan. + 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 SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 Reference 2: 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 + Details
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