Disaggregated Revenues - Summary of Revenues and Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenues	$ 135,563	$ 170,051	$ 289,327	$ 322,557
Net product sales
Disaggregation of Revenue [Line Items]
Total revenues	$ 128,336	$ 165,459	$ 268,911	$ 312,923
Net product sales | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	100.00%	100.00%	100.00%	100.00%
Qelbree
Disaggregation of Revenue [Line Items]
Total revenues	$ 30,977	$ 11,099	$ 56,759	$ 19,382
Qelbree | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	24.00%	7.00%	21.00%	6.00%
GOCOVRI
Disaggregation of Revenue [Line Items]
Total revenues	$ 28,751	$ 24,700	$ 54,761	$ 47,301
GOCOVRI | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	22.00%	15.00%	20.00%	15.00%
Oxtellar XR
Disaggregation of Revenue [Line Items]
Total revenues	$ 23,800	$ 29,958	$ 52,715	$ 57,479
Oxtellar XR | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	19.00%	18.00%	20.00%	18.00%
Trokendi XR
Disaggregation of Revenue [Line Items]
Total revenues	$ 19,319	$ 71,602	$ 54,109	$ 134,434
Trokendi XR | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	15.00%	43.00%	20.00%	43.00%
APOKYN
Disaggregation of Revenue [Line Items]
Total revenues	$ 17,605	$ 20,447	$ 34,814	$ 38,895
APOKYN | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	14.00%	12.00%	13.00%	12.00%
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 7,884	$ 7,653	$ 15,753	$ 15,432
Other | Revenue from Contract with Customer Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	6.00%	5.00%	6.00%	6.00%
Royalty revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 7,227	$ 4,592	$ 20,416	$ 9,634