License, Research and Collaboration Agreements - Supply Agreement - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Ampyra | Alkermes
Supply Agreement
Minimum agreed percentage of annual requirements for purchase	75.00%
Supply agreement
Supply Agreement
Compensatory payment	$ 0	$ 0
Supply agreement | Maximum | Patheon Inc Second Manufacturing agreement
Supply Agreement
Purchase requirements threshold percentage	25.00%
Supply agreement | Alkermes License Agreement | Ampyra | Alkermes
Supply Agreement
Minimum agreed percentage of annual requirements for purchase	75.00%
Supply agreement | Alkermes License Agreement | Maximum
Supply Agreement
Purchase requirements threshold percentage	100.00%