COVER PAGE - shares	3 Months Ended
	Mar. 31, 2020	May 05, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-38080
Entity Registrant Name	Biohaven Pharmaceutical Holding Company Ltd.
Entity Central Index Key	0001689813
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Incorporation, State or Country Code	D8
Entity Address, Address Line One	c/o Biohaven Pharmaceuticals, Inc.
Entity Address, Address Line Two	215 Church Street
Entity Address, City or Town	New Haven
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06510
City Area Code	203
Local Phone Number	404-0410
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Shares, no par value
Trading Symbol	BHVN
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		58,532,152