Basis of Presentation	12 Months Ended
Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION The accompanying Consolidated Financial Statements include the accounts of Open Text Corporation and our subsidiaries, collectively referred to as "OpenText" or the "Company". We wholly own all of our subsidiaries with the exception of Open Text South Africa Proprietary Ltd. (OT South Africa), GXS, Inc. (GXS Korea) and EC1 Pte. Ltd. (GXS Singapore), which as of June 30, 2018, were 70%, 85% and 81% owned, respectively, by OpenText. All inter-company balances and transactions have been eliminated. These Consolidated Financial Statements are expressed in U.S. dollars and are prepared in accordance with United States generally accepted accounting principles (U.S. GAAP). The information furnished reflects all adjustments necessary for a fair presentation of the results for the periods presented and includes the financial results of Covisint Corporation (Covisint), with effect from July 26, 2017, Guidance Software, Inc. (Guidance), with effect from September 14, 2017, and Hightail, Inc. (Hightail), with effect from February 14, 2018 (see note 18 "Acquisitions"). Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates, judgments and assumptions that affect the amounts reported in the Consolidated Financial Statements. These estimates, judgments and assumptions are evaluated on an ongoing basis. We base our estimates on historical experience and on various other assumptions that we believe are reasonable at that time, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from those estimates. In particular, significant estimates, judgments and assumptions include those related to: (i) revenue recognition, (ii) testing of goodwill for impairment, (iii) the valuation of acquired intangible assets, (iv) the valuation of long-lived assets, (v) the recognition of contingencies, (vi) restructuring accruals, (vii) acquisition accruals and pre-acquisition contingencies, (viii) the realization of investment tax credits, (ix) the valuation of stock options granted and obligations related to share-based payments, including the valuation of our long-term incentive plans, (x) the valuation of pension assets and obligations, and (xi) accounting for income taxes. Beginning in the second quarter of Fiscal 2018, our income tax estimates were impacted by legislation informally known as the Tax Cuts and Jobs Act, which was enacted in the United States on December 22, 2017. The Company has recorded a provisional charge and continues to assess the effect of the new law on its consolidated financial statements in accordance with Staff Accounting Bulletin 118 “Income Tax Accounting Implications of the Tax Cuts and Jobs Act” (SAB 118). For more details related to this matter, please refer to note 14 "Income Taxes".

BASIS OF PRESENTATION

The accompanying Consolidated Financial Statements include the accounts of Open Text Corporation and our subsidiaries, collectively referred to as "OpenText" or the "Company". We wholly own all of our subsidiaries with the exception of Open Text South Africa Proprietary Ltd. (OT South Africa), GXS, Inc. (GXS Korea) and EC1 Pte. Ltd. (GXS Singapore), which as of June 30, 2018, were 70%, 85% and 81% owned, respectively, by OpenText. All inter-company balances and transactions have been eliminated.

These Consolidated Financial Statements are expressed in U.S. dollars and are prepared in accordance with United States generally accepted accounting principles (U.S. GAAP). The information furnished reflects all adjustments necessary for a fair presentation of the results for the periods presented and includes the financial results of Covisint Corporation (Covisint), with effect from July 26, 2017, Guidance Software, Inc. (Guidance), with effect from September 14, 2017, and Hightail, Inc. (Hightail), with effect from February 14, 2018 (see note 18 "Acquisitions").

Use of estimates

The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates, judgments and assumptions that affect the amounts reported in the Consolidated Financial Statements. These estimates, judgments and assumptions are evaluated on an ongoing basis. We base our estimates on historical experience and on various other assumptions that we believe are reasonable at that time, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from those estimates. In particular, significant estimates, judgments and assumptions include those related to: (i) revenue recognition, (ii) testing of goodwill for impairment, (iii) the valuation of acquired intangible assets, (iv) the valuation of long-lived assets, (v) the recognition of contingencies, (vi) restructuring accruals, (vii) acquisition accruals and pre-acquisition contingencies, (viii) the realization of investment tax credits, (ix) the valuation of stock options granted and obligations related to share-based payments, including the valuation of our long-term incentive plans, (x) the valuation of pension assets and obligations, and (xi) accounting for income taxes. Beginning in the second quarter of Fiscal 2018, our income tax estimates were impacted by legislation informally known as the Tax Cuts and Jobs Act, which was enacted in the United States on December 22, 2017. The Company has recorded a provisional charge and continues to assess the effect of the new law on its consolidated financial statements in accordance with Staff Accounting Bulletin 118 “Income Tax Accounting Implications of the Tax Cuts and Jobs Act” (SAB 118). For more details related to this matter, please refer to note 14 "Income Taxes".