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Contracts Accounted for as Credit Derivatives - Credit Derivatives Subordination and Ratings (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
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Sep. 30, 2023 | Dec. 31, 2022
Credit Derivatives |  |
Estimated remaining weighted average life of credit derivatives (in years) | 11 years 4 months 24 days | 12 years 9 months 18 days
Net Par Outstanding on Credit Derivatives |  |
Net Par Outstanding | $ 3,489 | $ 3,203
Net Fair Value Asset (Liability) | (49) | (162)
Expected loss to be recovered | 3 | 3
Public finance | United States |  |
Net Par Outstanding on Credit Derivatives |  |
Net Par Outstanding | 1,074 | 1,175
Net Fair Value Asset (Liability) | (15) | (79)
Public finance | Non United States |  |
Net Par Outstanding on Credit Derivatives |  |
Net Par Outstanding | 1,478 | 1,565
Net Fair Value Asset (Liability) | (19) | (58)
Structured finance | United States |  |
Net Par Outstanding on Credit Derivatives |  |
Net Par Outstanding | 327 | 342
Net Fair Value Asset (Liability) | (13) | (22)
Structured finance | Non United States |  |
Net Par Outstanding on Credit Derivatives |  |
Net Par Outstanding | 610 | 121
Net Fair Value Asset (Liability) | $ (2) | $ (3)

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- Definition Expected Loss on Credit Derivative to Be Paid (Recovered), Including Representation and Warranty Liability (Benefit) + References No definition available. + Details
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Balance Type: | credit
Period Type: | instant

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- References No definition available. + Details
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- Definition Represents the outstanding principal amounts of the underlying insured obligations that are accounted for as credit derivatives, net of protection purchased. + References No definition available. + Details
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- Definition Average period covered by credit risk derivative contracts, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4K -Subparagraph (a)(1) -SubTopic 10 -Topic 815 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4K + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Fair value of credit risk derivative asset after deduction of credit risk derivative liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4K -Subparagraph (c) -SubTopic 10 -Topic 815 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4K + Details
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