Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 01, 2021	Jun. 27, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Entity File Number	001-32598
Document Transition Report	false
Entity Registrant Name	Entegris, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-1941551
Entity Address, Address Line One	129 Concord Road
Entity Address, City or Town	Billerica
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01821
City Area Code	978
Local Phone Number	436-6500
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	ENTG
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 6,656,221,289
Entity Common Stock, Shares Outstanding		134,933,582
Amendment Flag	false
Entity Central Index Key	0001101302
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY