Fair Value of Financial Instruments - Schedule of Major Categories of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Certificates of Deposit [Member] | ||
| Assets: | ||
| Assets | $ 75.0 | $ 75.1 |
| U.S. Treasury Securities [Member] | ||
| Assets: | ||
| Assets | 300.1 | 299.4 |
| Level 2 [Member] | Certificates of Deposit [Member] | ||
| Assets: | ||
| Assets | 75.0 | 75.1 |
| Level 2 [Member] | U.S. Treasury Securities [Member] | ||
| Assets: | ||
| Assets | $ 300.1 | $ 299.4 |