Subsequent Events - Additional Information (Details) - Abeona Rett Agreement - Abeona - Subsequent Event	Oct. 29, 2020 USD ($)
Subsequent Event [Line Items]
Payment of one-time upfront license fee	$ 3,000,000
Maximum
Subsequent Event [Line Items]
Regulatory related milestones obligation payable	26,500,000
Sale-related milestones per licensed product and royalties on net sales of licensed products payable	$ 30,000,000