Marketable Securities - Summary of Net Unrealized Gain (Loss) Recorded on Marketable Debt and Equity Securities (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Marketable Debt Securities [Member] | |||||
| Marketable Securities [Line Items] | |||||
| Unrealized (loss) gain recorded on marketable securities | $ (2.7) | $ (0.2) | $ (9.4) | $ 2.1 | |
| Unrealized (loss) gain position of marketable debt securities | (4.7) | (4.7) | $ 4.7 | ||
| Marketable Equity Securities [Member] | |||||
| Marketable Securities [Line Items] | |||||
| Unrealized (loss) gain recorded on marketable securities | 6.1 | $ 1.8 | (6.0) | $ (6.4) | |
| Unrealized gain position of marketable equity securities | $ 2.9 | $ 2.9 | $ 8.9 | ||