Cover Page - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jul. 24, 2020
Cover [Abstract]
Document Type		10-Q
Document Quarterly Report		true
Document Period End Date		Jun. 30, 2020
Document Transition Report		false
Entity File Number		001-36569
Entity Registrant Name		LANTHEUS HOLDINGS, INC.
Entity Incorporation, State or Country Code		DE
Entity Tax Identification Number		35-2318913
Entity Address, Address Line One		331 Treble Cove Road
Entity Address, Postal Zip Code		01862
Entity Address, City or Town		North Billerica,
Entity Address, State or Province		MA
City Area Code		(978)
Local Phone Number		671-8001
Title of 12(b) Security		Common stock, par value $0.01 per share
Trading Symbol		LNTH
Security Exchange Name		NASDAQ
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
Entity Common Stock, Shares Outstanding			66,813,380
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001521036
Current Fiscal Year End Date	--12-31