Document and Entity Information	3 Months Ended
	Mar. 31, 2019
Document And Entity Information [Abstract]
Document Type	S-4
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Entity Registrant Name	Elanco Animal Health Inc.
Entity Central Index Key	0001739104
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false