Reinsurance - Consolidated Property Casualty Insurance Assumed and Ceded Business (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Property Casualty Insurance Assumed And Ceded Business | ||||
| Earned premiums | $ 2,480 | $ 2,156 | $ 4,824 | $ 4,227 |
| Incurred loss and loss expenses | 1,660 | 1,480 | 3,628 | 2,829 |
| Consolidated Property And Casualty Insurance | ||||
| Property Casualty Insurance Assumed And Ceded Business | ||||
| Direct written premiums | 2,672 | 2,362 | 5,060 | 4,487 |
| Assumed written premiums | 196 | 236 | 499 | 475 |
| Ceded written premiums | (135) | (139) | (331) | (255) |
| Net written premiums | 2,733 | 2,459 | 5,228 | 4,707 |
| Direct earned premiums | 2,333 | 2,015 | 4,580 | 3,949 |
| Assumed earned premiums | 162 | 155 | 352 | 307 |
| Ceded earned premiums | (98) | (95) | (271) | (189) |
| Earned premiums | 2,397 | 2,075 | 4,661 | 4,067 |
| Direct incurred loss and loss expenses | 1,508 | 1,352 | 3,657 | 2,545 |
| Assumed incurred loss and loss expenses | 91 | 63 | 327 | 139 |
| Ceded incurred loss and loss expenses | (12) | (3) | (510) | (2) |
| Incurred loss and loss expenses | $ 1,587 | $ 1,412 | $ 3,474 | $ 2,682 |
| X | ||||||||||
- Definition [Line Items] for Property Casualty Insurance Premiums Written On Assumed And Ceded Business No definition available.
|
| X | ||||||||||
- Definition Amount of earned premiums assumed from other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of written premiums assumed from other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of earned premiums ceded to other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of written premiums ceded to other entities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums earned. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums written. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition The increase (decrease) in property and casualty insurance liabilities balances during the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount, before effect of policies assumed or ceded, of expense related to provision for policy benefits and costs incurred. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of policy benefits and costs incurred for policies assumed. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of reduction of provision for policy benefits and costs incurred for policies ceded. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Details
|