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Contracts Accounted for as Credit Derivatives - Distribution of Credit Derivative Net Par Outstanding by Internal Rating (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2023 | Dec. 31, 2022
Credit Derivatives |  |
Net Par Outstanding | $ 3,489 | $ 3,203
BIG |  |
Credit Derivatives |  |
Net Par Outstanding | 55 | 57
Credit Concentration Risk | Derivative, Aggregate Notional Amount |  |
Credit Derivatives |  |
Net Par Outstanding | $ 3,489 | $ 3,203
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 100.00% | 100.00%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | AAA |  |
Credit Derivatives |  |
Net Par Outstanding | $ 1,255 | $ 1,260
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 36.00% | 39.30%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | AA |  |
Credit Derivatives |  |
Net Par Outstanding | $ 1,020 | $ 1,064
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 29.20% | 33.20%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | A |  |
Credit Derivatives |  |
Net Par Outstanding | $ 689 | $ 232
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 19.70% | 7.20%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | BBB |  |
Credit Derivatives |  |
Net Par Outstanding | $ 470 | $ 590
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 13.50% | 18.50%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | BIG |  |
Credit Derivatives |  |
Net Par Outstanding | $ 55 | $ 57
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 1.60% | 1.80%

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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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