| Document and Entity Information | Apr. 23, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | ENTEGRIS INC |
| Amendment Flag | false |
| Entity Central Index Key | 0001101302 |
| Document Type | 8-K |
| Document Period End Date | Apr. 23, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-32598 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, $0.01 par value per share |
| Trading Symbol | ENTG |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
