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Financial Guarantee Insurance Contracts - Summary of Rollforward of RMBS Subrogation, by Estimation Approach (Parenthetical) (Detail) (Adverse Samples [Member]) | 2 Months Ended | 4 Months Ended
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Jun. 30, 2013 Transactions | Apr. 30, 2013 Transactions
Adverse Samples [Member] |  |
Summary Of Rollforward Of Subrogation By Estimation Approach [Line Items] |  |
Number of additional transactions added to Adverse Sample subrogation | 1 |
Number of additional transactions transferred from Random Sample to Adverse Sample population |  | 2

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- Definition Number of Additional Transactions Added to Subrogation Population + References No definition available. + Details
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- Definition Number of transactions transferred from Random Sample to Adverse Sample population. + References No definition available. + Details
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- Details
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