| Cover Document | Oct. 31, 2019 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Oct. 31, 2019 |
| Entity Registrant Name | Open Text Corp |
| Entity Incorporation, State or Country Code | Z4 |
| Entity File Number | 0-27544 |
| Entity Tax Identification Number | 98-0154400 |
| Entity Central Index Key | 0001002638 |
| Amendment Flag | false |
| Entity Address, Address Line One | 275 Frank Tompa Drive |
| Entity Address, City or Town | Waterloo |
| Entity Address, State or Province | ON |
| Entity Address, Country | CA |
| Entity Address, Postal Zip Code | N2L 0A1 |
| City Area Code | 519 |
| Local Phone Number | 888-7111 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock without par value |
| Trading Symbol | OTEX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
