Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jun. 09, 2020	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Valuation allowance related to acquisition	$ 70,529	$ 582	$ 11	$ 70,500	$ 9
Research and development credit carryforwards	1,600
Net tax benefit as a result of statutes of limitation	100	600	3,000
Tax expense on uncertain tax positions	300	$ 300	$ 200
Tax expense related to prior year position	200
Adamas Pharmaceuticals
Operating Loss Carryforwards [Line Items]
Valuation allowance related to acquisition	69,700
U.S. Federal
Operating Loss Carryforwards [Line Items]
NOL carryforwards	449,300
NOLs utilized	7,200
U.S. Federal | Adamas Pharmaceuticals
Operating Loss Carryforwards [Line Items]
NOL carryforwards	413,700
State
Operating Loss Carryforwards [Line Items]
NOL carryforwards	431,900
NOLs utilized	5,300
State | Adamas Pharmaceuticals
Operating Loss Carryforwards [Line Items]
NOL carryforwards	$ 387,300