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Fair Value Measurement - Financial Instruments Carried at Fair Value (Details) - USD ($) $ in Millions | Mar. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Assets: |  |
Estimated Fair Value | $ 6,415 | $ 6,369
Fixed-maturity securities, trading | 137 | 147
Short-term investments, at fair value | 1,158 | 1,221
Other invested assets | 960 | 926
Other assets | 134 | 131
Liabilities: |  |
FG VIEs' liabilities | 163 | 164
Other liabilities. fair value disclosure | 34 | 34
Obligations of state and political subdivisions |  |
Assets: |  |
Estimated Fair Value | 1,924 | 1,940
U.S. government and agencies |  |
Assets: |  |
Estimated Fair Value | 72 | 67
Corporate securities |  |
Assets: |  |
Estimated Fair Value | 2,477 | 2,382
RMBS |  |
Assets: |  |
Estimated Fair Value | 569 | 567
CMBS |  |
Assets: |  |
Estimated Fair Value | 182 | 186
Non-U.S. government securities |  |
Assets: |  |
Estimated Fair Value | 71 | 69
Recurring |  |
Assets: |  |
Estimated Fair Value | 6,415 | 6,369
Fixed-maturity securities, trading | 137 | 147
Short-term investments, at fair value | 1,158 | 1,221
Other invested assets | 3 | 4
Other assets | 134 | 131
Total assets carried at fair value | 8,110 | 8,118
Liabilities: |  |
Other liabilities. fair value disclosure | 34 | 34
Total liabilities carried at fair value | 197 | 198
Recurring | Financial Guaranty Variable Interest Entities |  |
Liabilities: |  |
FG VIEs' liabilities | 163 | 164
Recurring | Financial Guaranty Variable Interest Entities |  |
Assets: |  |
FG VIEs’ assets | 145 | 147
Recurring | Obligations of state and political subdivisions |  |
Assets: |  |
Estimated Fair Value | 1,924 | 1,940
Recurring | U.S. government and agencies |  |
Assets: |  |
Estimated Fair Value | 72 | 67
Recurring | Corporate securities |  |
Assets: |  |
Estimated Fair Value | 2,477 | 2,382
Recurring | RMBS |  |
Assets: |  |
Estimated Fair Value | 569 | 567
Recurring | CMBS |  |
Assets: |  |
Estimated Fair Value | 182 | 186
Recurring | Asset-backed securities |  |
Assets: |  |
Estimated Fair Value | 1,120 | 1,158
Recurring | Non-U.S. government securities |  |
Assets: |  |
Estimated Fair Value | 71 | 69
Recurring | Assets of CIVs, Equity Securities | Consolidated Investment Vehicles |  |
Assets: |  |
FG VIEs’ assets | 118 | 99
Recurring | Level 1 |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Fixed-maturity securities, trading | 0 | 0
Short-term investments, at fair value | 1,154 | 1,218
Other invested assets | 0 | 0
Other assets | 68 | 65
Total assets carried at fair value | 1,222 | 1,283
Liabilities: |  |
Other liabilities. fair value disclosure | 0 | 0
Total liabilities carried at fair value | 0 | 0
Recurring | Level 1 | Financial Guaranty Variable Interest Entities |  |
Liabilities: |  |
FG VIEs' liabilities | 0 | 0
Recurring | Level 1 | Financial Guaranty Variable Interest Entities |  |
Assets: |  |
FG VIEs’ assets | 0 | 0
Recurring | Level 1 | Obligations of state and political subdivisions |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | U.S. government and agencies |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | Corporate securities |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | RMBS |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | CMBS |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | Asset-backed securities |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | Non-U.S. government securities |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 1 | Assets of CIVs, Equity Securities | Consolidated Investment Vehicles |  |
Assets: |  |
FG VIEs’ assets | 0 | 0
Recurring | Level 2 |  |
Assets: |  |
Estimated Fair Value | 5,273 | 5,183
Fixed-maturity securities, trading | 132 | 142
Short-term investments, at fair value | 4 | 3
Other invested assets | 0 | 0
Other assets | 58 | 59
Total assets carried at fair value | 5,467 | 5,387
Liabilities: |  |
Other liabilities. fair value disclosure | 0 | 0
Total liabilities carried at fair value | 0 | 0
Recurring | Level 2 | Financial Guaranty Variable Interest Entities |  |
Liabilities: |  |
FG VIEs' liabilities | 0 | 0
Recurring | Level 2 | Financial Guaranty Variable Interest Entities |  |
Assets: |  |
FG VIEs’ assets | 0 | 0
Recurring | Level 2 | Obligations of state and political subdivisions |  |
Assets: |  |
Estimated Fair Value | 1,914 | 1,930
Recurring | Level 2 | U.S. government and agencies |  |
Assets: |  |
Estimated Fair Value | 72 | 67
Recurring | Level 2 | Corporate securities |  |
Assets: |  |
Estimated Fair Value | 2,472 | 2,382
Recurring | Level 2 | RMBS |  |
Assets: |  |
Estimated Fair Value | 425 | 422
Recurring | Level 2 | CMBS |  |
Assets: |  |
Estimated Fair Value | 182 | 186
Recurring | Level 2 | Asset-backed securities |  |
Assets: |  |
Estimated Fair Value | 137 | 127
Recurring | Level 2 | Non-U.S. government securities |  |
Assets: |  |
Estimated Fair Value | 71 | 69
Recurring | Level 2 | Assets of CIVs, Equity Securities | Consolidated Investment Vehicles |  |
Assets: |  |
FG VIEs’ assets | 0 | 0
Recurring | Level 3 |  |
Assets: |  |
Estimated Fair Value | 1,142 | 1,186
Fixed-maturity securities, trading | 5 | 5
Short-term investments, at fair value | 0 | 0
Other invested assets | 3 | 4
Other assets | 8 | 7
Total assets carried at fair value | 1,421 | 1,448
Liabilities: |  |
Other liabilities. fair value disclosure | 34 | 34
Total liabilities carried at fair value | 197 | 198
Recurring | Level 3 | Financial Guaranty Variable Interest Entities |  |
Liabilities: |  |
FG VIEs' liabilities | 163 | 164
Recurring | Level 3 | Financial Guaranty Variable Interest Entities |  |
Assets: |  |
FG VIEs’ assets | 145 | 147
Recurring | Level 3 | Obligations of state and political subdivisions |  |
Assets: |  |
Estimated Fair Value | 10 | 10
Recurring | Level 3 | U.S. government and agencies |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 3 | Corporate securities |  |
Assets: |  |
Estimated Fair Value | 5 | 0
Recurring | Level 3 | RMBS |  |
Assets: |  |
Estimated Fair Value | 144 | 145
Recurring | Level 3 | CMBS |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 3 | Asset-backed securities |  |
Assets: |  |
Estimated Fair Value | 983 | 1,031
Recurring | Level 3 | Non-U.S. government securities |  |
Assets: |  |
Estimated Fair Value | 0 | 0
Recurring | Level 3 | Assets of CIVs, Equity Securities | Consolidated Investment Vehicles |  |
Assets: |  |
FG VIEs’ assets | $ 118 | $ 99

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