Fair Value Measurements - Carrying Value of our Non-Marketable Equity Securities (Details) - USD ($) $ in Millions |
Mar. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|
| Fair Value Disclosures [Abstract] | ||
| Initial cost basis | $ 450 | $ 450 |
| Upward adjustments | 9 | 9 |
| Downward adjustments (including impairment) | (413) | (413) |
| Total carrying value at the end of reporting period | $ 46 | $ 46 |