LICENSE AGREEMENTS AND ASSET PURCHASE AGREEMENTS (Details) - USD ($) $ in Thousands	1 Months Ended									3 Months Ended		6 Months Ended
	Apr. 30, 2024	Mar. 31, 2023	Jul. 31, 2022	Mar. 31, 2022	Aug. 31, 2021	Jan. 31, 2021	Oct. 31, 2020	Nov. 30, 2019	Aug. 31, 2019	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Feb. 28, 2019
License Agreements and Asset Purchase Agreements
Cost of product sold										$ 32,144	$ 25,008	$ 59,628	$ 45,788
Accrued Sales Based Trademark and Royalties										30,199		30,199		$ 40,419
All Countries Excluding Greater China | HBS-102 | Asset Purchase Agreement with ConSynance Therapeutics
License Agreements and Asset Purchase Agreements
Consideration transferred					$ 3,500
Payment for intellectual property upon preclinical milestones					1,000
Payment for intellectual property upon developmental milestones					19,000
Payment for intellectual property upon regulatory milestones					44,000
Payment for intellectual property upon sales milestones					$ 110,000
All Countries Excluding Greater China | HBS-102 | Asset Purchase Agreement with ConSynance Therapeutics | Research and development expense
License Agreements and Asset Purchase Agreements
Payment related to achievement of preclinical milestone.		$ 750,000
Bioprojet
License Agreements and Asset Purchase Agreements
Licensing agreement milestone fees									$ 2,000
License agreement milestone payments paid								$ 75,000	2,000
License agreement, additional milestone payment due									102,000
Bioprojet | Upon Acceptance by FDA of Pitolisant's
License Agreements and Asset Purchase Agreements
License agreement, milestone payment due															$ 50,000
License agreement, upfront non-refundable licensing fees paid			$ 30,000
License agreement, maximum additional milestone payment due			$ 155,000
Bioprojet | Upon FDA Approval of WAKIX
License Agreements and Asset Purchase Agreements
License agreement, milestone payment due									77,000
Licensing agreement milestone fees									$ 2,000
License agreement milestone payments paid						$ 100,000	$ 2,000
Bioprojet | Sales-based, trademark and tiered royalties
License Agreements and Asset Purchase Agreements
Cost of product sold										30,199	$ 22,542	54,937	$ 41,602
Accrued Sales Based Trademark and Royalties										$ 30,199		30,199		$ 40,419
Bioprojet | Orexin-2 receptor agonist (OX2R)
License Agreements and Asset Purchase Agreements
Payment of upfront license fee	$ 25,500											$ 25,500
Amount of fee payable upon achieving development and regulatory milestones	127,500
Amount of fees payable upon achieving sale-based milestones	$ 240,000
Bioprojet | United States
License Agreements and Asset Purchase Agreements
Amount of Aggregate Net Sales Attaining				$ 500,000
Bioprojet | Attaining $500,000 Aggregate Net Sales | United States | Upon FDA Approval of WAKIX
License Agreements and Asset Purchase Agreements
Final payment paid				$ 40,000