INTANGIBLE ASSETS - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended				3 Months Ended		6 Months Ended
	Mar. 31, 2022	Feb. 28, 2022	Oct. 31, 2020	Aug. 31, 2019	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Intangible Assets
Net product revenue					$ 172,814	$ 134,216	$ 327,429	$ 253,342
Amortization expense					$ 5,961	$ 5,961	$ 11,922	$ 11,922
WAKIX
Intangible Assets
Useful life of intangible asset	7 years 7 months 6 days
Remaining useful life					5 years 3 months 18 days		5 years 3 months 18 days
Final payment paid	$ 40,000
WAKIX | United States
Intangible Assets
Net product revenue		$ 500,000
WAKIX | Daytime Sleepiness
Intangible Assets
License agreement milestone payments paid				$ 75,000
Useful life of intangible asset				10 years
Remaining useful life					5 years 3 months 18 days		5 years 3 months 18 days
NDA for WAKIX. | Cataplexy
Intangible Assets
License agreement milestone payments paid			$ 100,000
Useful life of intangible asset			9 years
Remaining useful life					5 years 3 months 18 days		5 years 3 months 18 days