Investments - Proceeds and Gross Gains/(Losses) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Available for Sale Securities, Gross Realized Gains (Losses), Proceeds on Sales | $ 1,125 | $ 797 | $ 2,125 | $ 1,967 |
| Debt Securities, Available-for-Sale, Realized Gain | 4 | 9 | 22 | 24 |
| Debt Securities, Available-for-Sale, Realized Loss | $ 17 | $ 5 | $ 34 | $ 32 |