Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 23, 2019
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2019
Entity File Number	001-12400
Entity Registrant Name	INCYTE CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3136539
Entity Address, Address Line One	1801 Augustine Cut-Off
Entity Address, City or Town	Wilmington
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19803
City Area Code	302
Local Phone Number	498-6700
Title of 12(b) Security	Common Stock, $.001 par value per share
Trading Symbol	INCY
Security Exchange Name	NASDAQ
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
Entity Common Stock, Shares Outstanding		215,066,629
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000879169
Amendment Flag	false