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v3.25.4

Transactions with Related Parties (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 USD ($) director | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items] |  |  |  |
Purchases of other investments | $ 2,238 | $ 3,485 | $ 2,171 |
Net premiums written | 16,476 | 15,732 | 13,468 |
Reinsurance recoverable for paid and unpaid claims and claims adjustments | 9,526 | 8,260 | 7,064 |
Reinsurance balances payable | 2,320 | 2,137 |  |
Other assets | 6,796 | 6,231 |  |
Other liabilities | $ 3,517 | $ 3,039 |  |
Premia Holdings Ltd |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Number of directors | director | 7 |  |  |
Greysbridge Holdings Ltd |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage ownership | 30.00% | 40.00% |  |
Equity Method Investee | Watford Insurance Company |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Consideration paid | $ 35 |  |  |
Equity Method Investee | Premia Holdings Ltd |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage ownership |  |  |  | 25.00%
Purchases of other investments |  |  |  | $ 100
Number of directors | director | 2 |  |  |
Funds held asset | $ 124 | $ 137 |  |
Equity Method Investee | Greysbridge Holdings Ltd |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Other assets | 162 |  |  |
Other liabilities | 162 |  |  |
Equity Method Investee | Somers Holdings Ltd. |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Net premiums written | 705 | 738 | $ 574 |
Reinsurance recoverable for paid and unpaid claims and claims adjustments | 2,000 | 1,600 |  |
Reinsurance balances payable | 550 | $ 489 |  |
Senior notes | $ 35 |  |  |
Preferred shares, dividend rate (as a percent) | 6.50% |  |  |

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