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Contracts Accounted for as Credit Derivatives - Distribution of Credit Derivative Net Par Outstanding by Internal Rating (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2023 | Dec. 31, 2022
Credit Derivatives |  |
Net Par Outstanding | $ 3,262 | $ 3,203
BIG |  |
Credit Derivatives |  |
Net Par Outstanding | 56 | 57
Credit Concentration Risk | Derivative, Aggregate Notional Amount |  |
Credit Derivatives |  |
Net Par Outstanding | $ 3,262 | $ 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 | $ 1,283 | $ 1,260
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 39.30% | 39.30%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | AA |  |
Credit Derivatives |  |
Net Par Outstanding | $ 1,071 | $ 1,064
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 32.80% | 33.20%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | A |  |
Credit Derivatives |  |
Net Par Outstanding | $ 254 | $ 232
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 7.80% | 7.20%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | BBB |  |
Credit Derivatives |  |
Net Par Outstanding | $ 598 | $ 590
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 18.40% | 18.50%
Credit Concentration Risk | Derivative, Aggregate Notional Amount | BIG |  |
Credit Derivatives |  |
Net Par Outstanding | $ 56 | $ 57
Percentage of installment premiums denominated in currencies other than the U.S. dollar | 1.70% | 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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