License Agreements and Asset Purchase Agreements (Details) - USD ($) $ in Thousands	1 Months Ended							3 Months Ended		9 Months Ended
	Mar. 31, 2023	Jul. 31, 2022	Aug. 31, 2021	Jan. 31, 2021	Oct. 31, 2020	Nov. 30, 2019	Aug. 31, 2019	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Feb. 28, 2019
License Agreements and Asset Purchase Agreements
Cost of product sold								$ 32,296	$ 22,959	$ 78,084	$ 56,596
Accrued Sales Based Trademark and Royalties								29,665		29,665		$ 25,367
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
Accrued Sales Based Trademark and Royalties								29,665		29,665		$ 25,367
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								$ 29,665	$ 20,944	71,267	$ 51,741
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