Insurance Liabilities - Discounting of reserves (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Discounting of Reserves [Line Items] | ||
| U.S. workers' compensation | $ 2,337,000,000 | $ 2,532,000,000 |
| Retroactive reinsurance | (1,104,000,000) | (1,254,000,000) |
| Total reserve discount | 1,233,000,000 | 1,278,000,000 |
| Fortitude RE | ||
| Discounting of Reserves [Line Items] | ||
| Total reserve discount | $ 687,000,000 | $ 763,000,000 |
| Discount ceded on sale (as a percent) | 100.00% | 100.00% |
| United Kingdom | ||
| Discounting of Reserves [Line Items] | ||
| Total reserve discount | $ 196,000,000 | $ 135,000,000 |