Disaggregated Revenues - Summary of Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenues	$ 607,521	$ 667,238	$ 579,775
Net product sales
Disaggregation of Revenue [Line Items]
Total revenues	$ 573,933	$ 649,432	$ 567,504
Net product sales | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	100.00%	100.00%	100.00%
Trokendi XR
Disaggregation of Revenue [Line Items]
Total revenues	$ 94,336	$ 261,221	$ 304,817
Trokendi XR | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	16.00%	40.00%	54.00%
Oxtellar XR
Disaggregation of Revenue [Line Items]
Total revenues	$ 113,404	$ 115,345	$ 110,708
Oxtellar XR | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	20.00%	18.00%	19.00%
GOCOVRI
Disaggregation of Revenue [Line Items]
Total revenues	$ 119,637	$ 104,421	$ 9,778
GOCOVRI | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	21.00%	16.00%	2.00%
APOKYN
Disaggregation of Revenue [Line Items]
Total revenues	$ 75,083	$ 75,305	$ 99,233
APOKYN | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	13.00%	12.00%	17.00%
Qelbree
Disaggregation of Revenue [Line Items]
Total revenues	$ 140,192	$ 61,322	$ 9,879
Qelbree | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	24.00%	9.00%	2.00%
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 31,281	$ 31,818	$ 33,089
Other | Percentage of Gross Product Sales | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	6.00%	5.00%	6.00%
Royalty and licensing revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 33,588	$ 17,806	$ 12,271