Name:	bhvn_MilestonePaymentToBePaidByCompanyUponSpecifiedRegulatoryMilestoneAchievement
Namespace Prefix:	bhvn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

No definition available.

Name:	bhvn_MilestonePaymentToBePaidByCompanyUponSpecifiedRegulatoryMilestoneAchievementSubsequentlyDevelopedProducts
Namespace Prefix:	bhvn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the number of claims if the Company abandons the sale of all products that will cause the reassignment of the applicable patent rights back to ALS Biopharma.

No definition available.

Name:	bhvn_NumberOfClaimsOfPatentsToReassign
Namespace Prefix:	bhvn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of prodrugs of glutamate modulating agents.

No definition available.

Name:	bhvn_NumberOfProdrugsOfGlutamateModulatingAgents
Namespace Prefix:	bhvn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.