Marketable Securities and Equity Investments - Net Unrealized Gains (Losses) (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||
| Net unrealized gains (losses) | $ 3.8 | $ (15.0) |