License, Acquisitions and Other Agreements (Details) $ in Thousands	Jun. 30, 2026 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Milestone payment to be paid upon development achievement	$ 139,313
Milestone payment to be paid upon regulatory achievement	711,600
Milestone payment to be paid upon commercial achievement	$ 3,187,488

Represents the amount of milestone payment to be paid by the company upon the achievement of specified commercial milestones and annual royalty payments based on net sales of products from patents.

No definition available.

Name:	bhvn_MilestonePaymentToBePaidByCompanyUponSpecifiedCommercialMilestoneAchievement
Namespace Prefix:	bhvn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant