| **Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions** | 3 Months Ended | 6 Months Ended |
|------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]**                                                    |           |           |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                 | $ 618          | $ 571          | $ 616 | $ 578 |
| Capitalized deferred policy acquisition costs                                                                                | 230            | 221            | 452 | 428 |
| Deferred Policy Acquisition Cost, Amortization Expense                                                                       | (214)          | (204)          | (426) | (413) |
| Deferred Policy Acquisition Cost, Amortization Expense, Other                                                                | (10)           | 12             | (18) | 7 |
| Deferred policy acquisition costs asset, end of period                                                                       | 624            | 600            | 624 | 600 |
| Life Insurance Product Line [Member]                                                                                         |           |           |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]**                                                    |           |           |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                 | 221            | 194            | 228 | 199 |
| Capitalized deferred policy acquisition costs                                                                                | 12             | 12             | 24 | 23 |
| Deferred Policy Acquisition Cost, Amortization Expense                                                                       | (11)           | (8)            | (22) | (19) |
| Deferred Policy Acquisition Cost, Amortization Expense, Other                                                                | (10)           | 12             | (18) | 7 |
| Deferred policy acquisition costs asset, end of period                                                                       | 212            | 210            | 212 | 210 |
| Consolidated Property and Casualty Insurance Entity                                                                          |           |           |   |   |
| **Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]**                                                    |           |           |   |   |
| Deferred policy acquisition costs asset, beginning of period                                                                 | 397            | 377            | 388 | 379 |
| Capitalized deferred policy acquisition costs                                                                                | 218            | 209            | 428 | 405 |
| Deferred Policy Acquisition Cost, Amortization Expense                                                                       | (203)          | (196)          | (404) | (394) |
| Deferred policy acquisition costs asset, end of period                                                                       | $ 412          | $ 390          | $ 412 | $ 390 |

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of expense related to deferred policy acquisition costs.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of other increase (decrease) to amortization expense of deferred policy acquisition cost (DAC).
+ References
No definition available.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Net amount of deferred policy acquisition costs capitalized on contracts remaining in force as of the balance sheet date.
+ References
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| - Definition
Total amount of policy acquisition costs capitalized during the income statement period.
+ 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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