Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended				3 Months Ended		9 Months Ended
	Mar. 31, 2022	Feb. 28, 2022	Jan. 31, 2021	Aug. 31, 2019	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Finite Lived Intangible Assets [Line Items]
Amortization expense					$ 5,962	$ 4,573	$ 17,005	$ 13,781
Net product revenues					$ 117,206	$ 80,732	$ 309,547	$ 214,227
WAKIX
Finite Lived Intangible Assets [Line Items]
Final payment paid	$ 40,000
Useful life of intangible asset							7 years 7 months 6 days
Remaining useful life							7 years
WAKIX | United States
Finite Lived Intangible Assets [Line Items]
Net product revenues		$ 500,000
WAKIX | Daytime Sleepiness
Finite Lived Intangible Assets [Line Items]
License agreement milestone payments paid				$ 75,000
Useful life of intangible asset							10 years
Remaining useful life							7 years
NDA for WAKIX. | Cataplexy
Finite Lived Intangible Assets [Line Items]
License agreement milestone payments paid			$ 100,000
Useful life of intangible asset			9 years
Remaining useful life							7 years