Investments - Unrealized Gains (Losses) Included in the Carrying Value of Measurement Alternative Investments (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Investments, Debt and Equity Securities [Abstract] | ||
| Alternative Investments, Upward Price Adjustment, Annual Amount | $ 7 | $ 0 |
| Alternative Investment, Downward Price Adjustment Including Impairment, Annual Amount | (3) | (133) |
| Equity Securities, FV-NI, Unrealized Gain (Loss) | $ 7 | $ (66) |