Investments - Carrying Value of Measurement Alternative Investments (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Investments, Debt and Equity Securities [Abstract] | ||
| Alternative Investment, Initial Cost Basis | $ 1,045 | |
| Alternative Investment, Upward Price Adjustment, Cumulative Amount | 529 | |
| Alternative Investment, Downward Price Adjustment Including Impairment, Cumulative Amount | (267) | |
| Measurement alternative | $ 1,307 | $ 1,242 |