Insurance Liabilities - Discounting of Reserves (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Discounting of Reserves [Line Items] | ||
| U.S. workers' compensation | $ 2,063 | $ 2,111 |
| Retroactive reinsurance | (891) | (936) |
| Total reserve discount | 1,172 | 1,175 |
| Fortitude RE | ||
| Discounting of Reserves [Line Items] | ||
| Total reserve discount | $ 693 | $ 627 |
| Discount ceded on sale (as a percent) | 100.00% | 100.00% |
| United Kingdom | ||
| Discounting of Reserves [Line Items] | ||
| Total reserve discount | $ 166 | $ 184 |