| **Reserves in Addition to Account Balance, Based on Expected No-Lapse Guarantee Benefits and Expected Policy Assessments (Details) - USD ($) $ in Millions** | Sep. 30, 2024 | Dec. 31, 2023 | Sep. 30, 2023 |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|---------------|
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | $ 3,069       | $ 3,068       |          |
| Life policy reserves:                                                                                                                                        |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 1,649         | 1,597         |          |
| Investment contract reserves:                                                                                                                                |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 1,420         | 1,471         |          |
| Term Life Insurance | Life policy reserves:                                                                                                                  |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 1,108         | 1,066         | $ 956         |
| Whole Life Insurance | Life policy reserves:                                                                                                                 |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 441           | 434           | $ 381         |
| Long-Duration Insurance, Other | Life policy reserves:                                                                                                       |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 100           | 97            |          |
| Long-Duration Insurance, Other | Investment contract reserves:                                                                                               |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 107           | 107           |          |
| Deferred Fixed Annuity | Investment contract reserves:                                                                                                       |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 605           | 656           |          |
| Universal life | Investment contract reserves:                                                                                                               |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | 590           | 585           |          |
| Structured Settlement Annuity | Investment contract reserves:                                                                                                |          |          |          |
| **Liability for Future Policy Benefit, by Product Segment**                                                                                                  |          |          |          |
| Life policy and investment contract reserves                                                                                                                 | $ 118         | $ 123         |          |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount, before effect of reinsurance, of present value of future benefit to be paid to or on behalf of policyholder and related expense less present value of future net premium receivable under insurance contract.
+ References
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