| Line Item | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 | Sep 30, 2023 | Jun 30, 2023 | Mar 31, 2023 | Dec 31, 2022 | Sep 30, 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operating expenses: | ||||||||||||||||
| Research and development | ||||||||||||||||
| General and administrative | ||||||||||||||||
| Gain on sale of in-process research and development asset | ||||||||||||||||
| Total operating expenses | ||||||||||||||||
| Loss from operations | ||||||||||||||||
| Other income (expense): | ||||||||||||||||
| Interest income | ||||||||||||||||
| Other (expense) income, net | ||||||||||||||||
| Total other income (expense) | ||||||||||||||||
| Loss before income tax expense | ||||||||||||||||
| Income tax benefit | ||||||||||||||||
| Net loss | ||||||||||||||||
| Net loss per share, basic (in dollars per share) | — | — | — | — | ||||||||||||
| Net loss per share, diluted (in dollars per share) | — | — | — |