Employee Termination Benefits - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | 14 Months Ended | ||
|---|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2026 |
Mar. 31, 2025 |
Sep. 30, 2025 |
|
| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | |||||
| Restructuring cost and reserve | $ 0.0 | $ 5.9 | |||
| Research and Development | |||||
| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | |||||
| Restructuring cost and reserve | $ 0.2 | $ 1.8 | |||
| General and administrative | |||||
| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] | |||||
| Restructuring cost and reserve | $ 0.8 | $ 0.1 | $ 3.6 | ||