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Contracts Accounted for as Insurance - Loss and LAE Reserve and Salvage and Subrogation Recoverable Net of Reinsurance (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
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Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | $ 75 | $ 37
Public finance | Financial Guarantee Insurance And Other Product Line | Consolidated Entity Excluding Variable Interest Entities (VIE) |  |
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | 120 | 72
Other structured finance | Financial Guarantee Insurance And Other Product Line | Consolidated Entity Excluding Variable Interest Entities (VIE) |  |
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | 42 | 42
Structured finance | Financial Guarantee Insurance And Other Product Line | Consolidated Entity Excluding Variable Interest Entities (VIE) |  |
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | (45) | (35)
U.S. | Public finance | Financial Guarantee Insurance And Other Product Line | Consolidated Entity Excluding Variable Interest Entities (VIE) |  |
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | 119 | 71
U.S. | RMBS | Financial Guarantee Insurance And Other Product Line | Consolidated Entity Excluding Variable Interest Entities (VIE) |  |
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | (87) | (77)
Non U.S. | Public finance | Financial Guarantee Insurance And Other Product Line | Consolidated Entity Excluding Variable Interest Entities (VIE) |  |
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items] |  |
Net reserve (salvage) | $ 1 | $ 1

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- Definition [Line Items] for Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Table] + References No definition available. + Details
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- Definition Represents the reserve for losses and loss adjustment expenses, net of reinsurance recoverable on unpaid losses and net of salvage and subrogation recoverable. + References No definition available. + Details
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