| **Deferred Policy Acquisition Costs - Life Deferred Acquisition Costs Rollforward by Product (Details) - USD ($) $ in Millions** | 12 Months Ended |
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| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |            |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | $ 1,013         | $ 916 | $ 838 |
| Deferred Policy Acquisition Cost, Capitalization                                                                                 | 1,530           | 1,427 | 1,254 |
| Deferred Policy Acquisition Costs, Amortization Expense                                                                          | (1,450)         | (1,330) | (1,176) |
| Deferred policy acquisition costs asset, end of period                                                                           | 1,093           | 1,013 | 916 |
| Term Life Insurance                                                                                                              |            |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |            |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 228             | 215 | 201 |
| Deferred Policy Acquisition Cost, Capitalization                                                                                 | 30              | 34 | 35 |
| Deferred Policy Acquisition Costs, Amortization Expense                                                                          | (22)            | (21) | (21) |
| Deferred policy acquisition costs asset, end of period                                                                           | 236             | 228 | 215 |
| Whole Life Insurance                                                                                                             |            |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |            |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 43              | 38 | 35 |
| Deferred Policy Acquisition Cost, Capitalization                                                                                 | 8               | 7 | 5 |
| Deferred Policy Acquisition Costs, Amortization Expense                                                                          | (3)             | (2) | (2) |
| Deferred policy acquisition costs asset, end of period                                                                           | 48              | 43 | 38 |
| Deferred Fixed Annuity                                                                                                           |            |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |            |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 7               | 7 | 6 |
| Deferred Policy Acquisition Cost, Capitalization                                                                                 | 2               | 1 | 1 |
| Deferred Policy Acquisition Costs, Amortization Expense                                                                          | (1)             | (1) | 0 |
| Deferred policy acquisition costs asset, end of period                                                                           | 8               | 7 | 7 |
| Universal Life                                                                                                                   |            |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |            |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 53              | 54 | 54 |
| Deferred Policy Acquisition Cost, Capitalization                                                                                 | 2               | 2 | 2 |
| Deferred Policy Acquisition Costs, Amortization Expense                                                                          | (3)             | (3) | (2) |
| Deferred policy acquisition costs asset, end of period                                                                           | 52              | 53 | 54 |
| Life Insurance Segment                                                                                                           |            |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs**                                                                       |            |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                     | 331             | 314 | 296 |
| Deferred Policy Acquisition Cost, Capitalization                                                                                 | 42              | 44 | 43 |
| Deferred Policy Acquisition Costs, Amortization Expense                                                                          | (29)            | (27) | (25) |
| Deferred policy acquisition costs asset, end of period                                                                           | $ 344           | $ 331 | $ 314 |

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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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