Investments - Unrealized Gains (Losses) Included in the Carrying Value of Measurement Alternative Investments (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2024 |
Jun. 30, 2023 |
Jun. 30, 2024 |
Jun. 30, 2023 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Alternative Investments, Upward Price Adjustment, Annual Amount | $ 0 | $ 6 | $ 7 | $ 6 |
| Alternative Investment, Downward Price Adjustment Including Impairment, Annual Amount | (1) | (2) | (4) | (135) |
| Equity Securities, FV-NI, Unrealized Gain (Loss) | $ (21) | $ 121 | $ (14) | $ 55 |