| **Deferred Policy Acquisition Costs - Life Deferred Acquisition Costs Rollforward by Product (Details) - USD ($) $ in Millions** | 3 Months Ended |
|----------------------------------------------------------------------------------------------------------------------------------|----------------|
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| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |           |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | $ 1,013        | $ 916 |
| Capitalized deferred policy acquisition costs                                                                                    | 383            | 376 |
| Amortized deferred policy acquisition costs                                                                                      | (348)          | (308) |
| Deferred policy acquisition costs asset, end of period                                                                           | 1,048          | 984 |
| Term Life Insurance                                                                                                              |           |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |           |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 228            | 215 |
| Capitalized deferred policy acquisition costs                                                                                    | 9              | 10 |
| Amortized deferred policy acquisition costs                                                                                      | (6)            | (5) |
| Deferred policy acquisition costs asset, end of period                                                                           | 231            | 220 |
| Whole Life Insurance                                                                                                             |           |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |           |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 43             | 38 |
| Capitalized deferred policy acquisition costs                                                                                    | 2              | 2 |
| Amortized deferred policy acquisition costs                                                                                      | (1)            | (1) |
| Deferred policy acquisition costs asset, end of period                                                                           | 44             | 39 |
| Deferred Fixed Annuity                                                                                                           |           |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |           |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 7              | 7 |
| Capitalized deferred policy acquisition costs                                                                                    | 0              | 0 |
| Amortized deferred policy acquisition costs                                                                                      | 0              | 0 |
| Deferred policy acquisition costs asset, end of period                                                                           | 7              | 7 |
| Universal life                                                                                                                   |           |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |           |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 53             | 54 |
| Capitalized deferred policy acquisition costs                                                                                    | 0              | 0 |
| Amortized deferred policy acquisition costs                                                                                      | (1)            | (1) |
| Deferred policy acquisition costs asset, end of period                                                                           | 52             | 53 |
| Life Insurance Segment                                                                                                           |           |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |           |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 331            | 314 |
| Capitalized deferred policy acquisition costs                                                                                    | 11             | 12 |
| Amortized deferred policy acquisition costs                                                                                      | (8)            | (7) |
| Deferred policy acquisition costs asset, end of period                                                                           | $ 334          | $ 319 |

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| - Definition
Amount of amortization expense (reversal of expense) for deferred policy acquisition costs.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of deferred policy acquisition cost capitalized on contract remaining in force.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of deferred policy acquisition cost capitalized.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.
+ References
No definition available.
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