Investments - Gross realized gains and gross realized losses from sales or maturities of available for sale securities (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Fixed maturity securities | ||
| Gross Realized Gains | $ 3 | $ 46 |
| Gross Realized Losses | (345) | (139) |
| Net Investment Income [Line Items] | ||
| Aggregate fair value of available for sale securities sold | 2,500 | 2,700 |
| Net realized gains (losses) | (342) | (93) |
| Fortitude RE Funds Withheld Assets | ||
| Net Investment Income [Line Items] | ||
| Net realized gains (losses) | $ (22) | $ (17) |