| **Investments (Contractual Maturity Dates For Fixed-Maturity And Short-Term Investments) (Details) - USD ($) $ in Millions** | Dec. 31, 2022 | Dec. 31, 2021 |
|------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Amortized cost**                                                                                                           |          |          |
| Due in one year or less                                                                                                      | $ 713         |          |
| Due after one year through five years                                                                                        | 3,966         |          |
| Due after five years through ten years                                                                                       | 3,533         |          |
| Due after ten years                                                                                                          | 4,767         |          |
| Total                                                                                                                        | 12,979        | $ 12,230      |
| **Fair value**                                                                                                               |          |          |
| Due in one year or less                                                                                                      | 709           |          |
| Due after one year through five years                                                                                        | 3,834         |          |
| Due after five years through ten years                                                                                       | 3,357         |          |
| Due after ten years                                                                                                          | 4,232         |          |
| Total                                                                                                                        | $ 12,132      | $ 13,022      |
| **% of fair value**                                                                                                          |          |          |
| Due in one year or less                                                                                                      | 5.80%         |          |
| Due after one year through five years                                                                                        | 31.60%        |          |
| Due after five years through ten years                                                                                       | 27.70%        |          |
| Due after ten years                                                                                                          | 34.90%        |          |
| Total                                                                                                                        | 100.00%       |          |

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