Income Taxes	3 Months Ended
Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10.Income Taxes For the three months ended September 30, 2018 and 2017, the Company recorded income tax provision of $1.4 million and $1.7 million, respectively. The income tax provisions for the three months ended September 30, 2018 and 2017, consisted primarily of taxes on the income of the Company’s foreign subsidiaries as well as tax expense associated with the establishment of a U.S. deferred tax liability for amortizable goodwill resulting from the acquisition of Enterasys Networks, Inc., the WLAN Business, the Campus Fabric Business and for the three months ended September 30, 2018, the Data Center Business. The income tax provisions for both fiscal years were calculated based on the actual results of operations for the three months ended September 30, 2018 and 2017, respectively and therefore may not reflect the annual effective tax rate. On December 22, 2017, the President of the United States signed and enacted into law H.R. 1, the Tax Cuts and Jobs Act (“TCJA”), which, except for certain provisions, is effective for the Company’s fiscal year ended 2019. As a fiscal year taxpayer, the Company was not subject to the majority of the tax law provisions until the first quarter of fiscal year 2019; however, there were certain significant items of impact that were recognized in fiscal year 2018, the year the TCJA was enacted. The TCJA’s primary change is a reduction in the U.S. Federal statutory corporate tax rate from 35% to 21%. As a result, the Company recognized a tax benefit in the amount of $2.5 million in the second quarter of fiscal 2018 due to the revaluation of the Company's deferred tax liability related to amortizable goodwill to reflect the lower statutory rate. Because the U.S. deferred tax assets are offset by a full valuation allowance, the reduction in deferred tax assets for the lower rate was fully offset by a corresponding reduction in valuation allowance resulting in no additional tax provision. The TCJA moves the U.S. from a global taxation regime to a modified territorial regime. Under the territorial regime, the company’s foreign earnings will generally not be subject to tax in the US. As part of transitioning to this new regime, U.S. companies were required to pay tax on historical earnings generated offshore that have not been repatriated to the U.S. (“Transition Tax”). The Company has estimated there will be no incremental tax provision relating to the Transition Tax given the Company’s ability to utilize existing tax attributes to offset the impact of the deemed repatriation. The TCJA makes broad and complex changes to the U.S. tax code, and in certain instances, lacks clarity and is subject to interpretation until additional U.S. Treasury guidance is issued. On December 22, 2017, the SEC issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”), which allows registrants to record provisional amounts during a one year “measurement period” similar to that used when accounting for business combinations. However, the measurement period is deemed to have ended earlier when the registrant has obtained, prepared and analyzed the information necessary to finalize its accounting. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared or analyzed. SAB 118 summarizes a three-step process to be applied at each reporting period to account for and qualitatively disclose: (1) the effects of the change in tax law for which accounting is complete; (2) provisional amounts (or adjustments to provisional amounts) for the effects of the tax law where accounting is not complete, but that a reasonable estimate has been determined; and (3) a reasonable estimate cannot yet be made and therefore taxes are reflected in accordance with law prior to the enactment of the TCJA. Amounts recorded where accounting is complete principally relate to the reduction in the U.S. federal tax rate to 21 percent, which resulted in the Company reporting an income tax benefit of $2.5 million in the fiscal year ended June 30, 2018 to remeasure deferred tax liabilities associated with indefinitely lived intangible assets that will reverse at the new 21% rate. Absent this deferred tax liability, the Company is in a net deferred tax asset position that is offset by a full valuation allowance. Though the impact of the rate change related to net deferred tax assets has a net tax effect of zero, the accounting to determine the gross change in the deferred tax position and the offsetting valuation is not yet complete. In accordance with SAB 118, the estimated income tax impact associated with the Transition Tax of zero represents our best estimate based on interpretation of the U.S. legislation as we are still accumulating data to finalize the underlying calculation. In accordance with SAB 118, estimated income tax impact associated with the Transition Tax is considered provisional and will be finalized prior to the end of the measurement period. The ultimate impact may differ from these provisional amounts, due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the TCJA. With respect to provisions of the TCJA effective for the Company’s fiscal year ended 2019, the Company anticipates several new provisions may potentially impact tax provisions in future periods including limitations on the deductibility of interest expense and certain executive compensation, a minimum tax on certain foreign earnings (i.e., global intangible low-taxed income or “GILTI”). The GILTI provisions require the Company to include in its U.S. income tax return foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. Based on initial assessment and interpretation of the new provision, the Company expects that it will be subject to incremental U.S. tax on GILTI income beginning in fiscal 2019. The Company may elect to account for GILTI tax as a component of tax expense in the period in which it is incurred or account for the GILTI tax in the measurement of deferred taxes. The Company is continuing to evaluate this particular provision and therefore has not yet elected a method but will do so once our analysis is complete. The Base Erosion and Anti-Abuse Tax (“BEAT”) provisions in the Tax Reform Act eliminate the deduction of certain base-erosion payments made to related foreign corporations and impose a minimum tax if greater than regular tax. There is a reasonable amount of uncertainty surrounding the interpretation of this new provision, however, based on initial assessment and a reasonable interpretation of the new provision, the Company expects that it will not be subject to the incremental U.S. tax on BEAT income beginning in fiscal 2019, due to a realignment of the Company’s international structure. In the three months ended September 30, 2019, the Company adopted ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory, which requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset at the time the transfer occurs. Historically, GAAP has prohibited the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset had been sold outside the consolidated group. Effective as of July 1, 2018, the Company adopted ASU 2016-16 on a modified retrospective basis which requires an adjustment of the cumulative-effect of the adoption to retained earnings. However, the adjustment was immaterial to the financial statements and no such adjustment was necessary. As a result of adoption, the income tax consequences of future intra-entity transfer of assets will be recognized in earnings in each period rather than be deferred until the assets leave the consolidated group. In the three months ended September 30, 2018, the Company recognized a deferred tax asset relating to a transfer of certain assets from the US parent company to its wholly-owned Irish subsidiary of $5.4 million, which was fully offset by the establishment of a valuation allowance resulting in no impact to Company’s statement of operations. The Company has provided a full valuation allowance against all of its U.S. federal and state deferred tax assets as well as the deferred tax assets in Australia and a portion of the deferred tax assets in Ireland. A valuation allowance is determined by assessing both negative and positive evidence to determine whether it is “more likely than not” that the deferred tax assets are recoverable; such assessment is required on a jurisdiction by jurisdiction basis. The Company's inconsistent earnings in recent periods, including a cumulative loss over the last three years, coupled with its difficulty in forecasting future revenue trends as well as the cyclical nature of its business represent sufficient negative evidence to require a full valuation allowance against its U.S. federal and state net deferred tax assets as well as the above mentioned foreign jurisdictions. This valuation allowance will be evaluated periodically and can be reversed partially or in whole if business results and the economic environment have sufficiently improved to support realization of some or all of the Company's deferred tax assets. The acquisition of Enterasys in October 2013 included a U.S. parent company as well as its wholly-owned foreign subsidiaries. The Company elected to treat this stock acquisition as an asset purchase by filing the required election forms under IRC Sec 338(h)(10). In addition, the Company completed asset purchases of the WLAN Business, the Campus Fabric Business and the Data Center Business in October 2016, July 2017 and October 2017, respectively. The Company has estimated the value of the intangible assets from these transactions and is amortizing the amounts over 15 years for tax purposes. During the three months ended September 30, 2018 and 2017, the Company deducted $0.5 million and $1.6 million of tax amortization expense respectively, for each period related to capitalized goodwill resulting from these acquisitions. As of September 30, 2018, the Company recorded a deferred tax liability of $5.9 million related to this goodwill amortization which is not considered a future source of taxable income in evaluating the need for a valuation allowance against its deferred tax assets. The Company had $17.2 million of unrecognized tax benefits as of September 30, 2018. The future impact of the unrecognized tax benefit of $17.2 million, if recognized, would result in adjustments to deferred tax assets and corresponding adjustments to the valuation allowance. The Company does not anticipate any events to occur during the next twelve months that would reduce the unrealized tax benefit as currently stated in the Company’s balance sheet. The Company’s policy is to accrue interest and penalties related to the underpayment of income taxes as a component of tax expense in the accompanying condensed consolidated statements of operations. In general, the Company’s U.S. federal income tax returns are subject to examination by tax authorities for fiscal years 2001 forward due to net operating losses and the Company's state income tax returns are subject to examination for fiscal years 2000 forward due to net operating losses. The Company is in the process of settling examination by the state of North Carolina for fiscal years ended 2014, 2015 and 2016. The settlement will result in an immaterial payment to the state to close all three years.

10.Income Taxes

For the three months ended September 30, 2018 and 2017, the Company recorded income tax provision of $1.4 million and $1.7 million, respectively.

The income tax provisions for the three months ended September 30, 2018 and 2017, consisted primarily of taxes on the income of the Company’s foreign subsidiaries as well as tax expense associated with the establishment of a U.S. deferred tax liability for amortizable goodwill resulting from the acquisition of Enterasys Networks, Inc., the WLAN Business, the Campus Fabric Business and for the three months ended September 30, 2018, the Data Center Business. The income tax provisions for both fiscal years were calculated based on the actual results of operations for the three months ended September 30, 2018 and 2017, respectively and therefore may not reflect the annual effective tax rate.

On December 22, 2017, the President of the United States signed and enacted into law H.R. 1, the Tax Cuts and Jobs Act (“TCJA”), which, except for certain provisions, is effective for the Company’s fiscal year ended 2019. As a fiscal year taxpayer, the Company was not subject to the majority of the tax law provisions until the first quarter of fiscal year 2019; however, there were certain significant items of impact that were recognized in fiscal year 2018, the year the TCJA was enacted.

The TCJA’s primary change is a reduction in the U.S. Federal statutory corporate tax rate from 35% to 21%. As a result, the Company recognized a tax benefit in the amount of $2.5 million in the second quarter of fiscal 2018 due to the revaluation of the Company's deferred tax liability related to amortizable goodwill to reflect the lower statutory rate. Because the U.S. deferred tax assets are offset by a full valuation allowance, the reduction in deferred tax assets for the lower rate was fully offset by a corresponding reduction in valuation allowance resulting in no additional tax provision.

The TCJA moves the U.S. from a global taxation regime to a modified territorial regime. Under the territorial regime, the company’s foreign earnings will generally not be subject to tax in the US. As part of transitioning to this new regime, U.S. companies were required to pay tax on historical earnings generated offshore that have not been repatriated to the U.S. (“Transition Tax”). The Company has estimated there will be no incremental tax provision relating to the Transition Tax given the Company’s ability to utilize existing tax attributes to offset the impact of the deemed repatriation.

The TCJA makes broad and complex changes to the U.S. tax code, and in certain instances, lacks clarity and is subject to interpretation until additional U.S. Treasury guidance is issued. On December 22, 2017, the SEC issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”), which allows registrants to record provisional amounts during a one year “measurement period” similar to that used when accounting for business combinations. However, the measurement period is deemed to have ended earlier when the registrant has obtained, prepared and analyzed the information necessary to finalize its accounting. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared or analyzed. SAB 118 summarizes a three-step process to be applied at each reporting period to account for and qualitatively disclose: (1) the effects of the change in tax law for which accounting is complete; (2) provisional amounts (or adjustments to provisional amounts) for the effects of the tax law where accounting is not complete, but that a reasonable estimate has been determined; and (3) a reasonable estimate cannot yet be made and therefore taxes are reflected in accordance with law prior to the enactment of the TCJA.

Amounts recorded where accounting is complete principally relate to the reduction in the U.S. federal tax rate to 21 percent, which resulted in the Company reporting an income tax benefit of $2.5 million in the fiscal year ended June 30, 2018 to remeasure deferred tax liabilities associated with indefinitely lived intangible assets that will reverse at the new 21% rate. Absent this deferred tax liability, the Company is in a net deferred tax asset position that is offset by a full valuation allowance. Though the impact of the rate change related to net deferred tax assets has a net tax effect of zero, the accounting to determine the gross change in the deferred tax position and the offsetting valuation is not yet complete. In accordance with SAB 118, the estimated income tax impact associated with the Transition Tax of zero represents our best estimate based on interpretation of the U.S. legislation as we are still accumulating data to finalize the underlying calculation. In accordance with SAB 118, estimated income tax impact associated with the Transition Tax is considered provisional and will be finalized prior to the end of the measurement period. The ultimate impact may differ from these provisional amounts, due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the TCJA.

With respect to provisions of the TCJA effective for the Company’s fiscal year ended 2019, the Company anticipates several new provisions may potentially impact tax provisions in future periods including limitations on the deductibility of interest expense and certain executive compensation, a minimum tax on certain foreign earnings (i.e., global intangible low-taxed income or “GILTI”). The GILTI provisions require the Company to include in its U.S. income tax return foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. Based on initial assessment and interpretation of the new provision, the Company expects that it will be subject to incremental U.S. tax on GILTI income beginning in fiscal 2019. The Company may elect to account for GILTI tax as a component of tax expense in the period in which it is incurred or account for the GILTI tax in the measurement of deferred taxes. The Company is continuing to evaluate this particular provision and therefore has not yet elected a method but will do so once our analysis is complete. The Base Erosion and Anti-Abuse Tax (“BEAT”) provisions in the Tax Reform Act eliminate the deduction of certain base-erosion payments made to related foreign corporations and impose a minimum tax if greater than regular tax. There is a reasonable amount of uncertainty surrounding the interpretation of this new provision, however, based on initial assessment and a reasonable interpretation of the new provision, the Company expects that it will not be subject to the incremental U.S. tax on BEAT income beginning in fiscal 2019, due to a realignment of the Company’s international structure.

In the three months ended September 30, 2019, the Company adopted ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory, which requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset at the time the transfer occurs. Historically, GAAP has prohibited the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset had been sold outside the consolidated group. Effective as of July 1, 2018, the Company adopted ASU 2016-16 on a modified retrospective basis which requires an adjustment of the cumulative-effect of the adoption to retained earnings. However, the adjustment was immaterial to the financial statements and no such adjustment was necessary. As a result of adoption, the income tax consequences of future intra-entity transfer of assets will be recognized in earnings in each period rather than be deferred until the assets leave the consolidated group. In the three months ended September 30, 2018, the Company recognized a deferred tax asset relating to a transfer of certain assets from the US parent company to its wholly-owned Irish subsidiary of $5.4 million, which was fully offset by the establishment of a valuation allowance resulting in no impact to Company’s statement of operations.

The Company has provided a full valuation allowance against all of its U.S. federal and state deferred tax assets as well as the deferred tax assets in Australia and a portion of the deferred tax assets in Ireland. A valuation allowance is determined by assessing both negative and positive evidence to determine whether it is “more likely than not” that the deferred tax assets are recoverable; such assessment is required on a jurisdiction by jurisdiction basis. The Company's inconsistent earnings in recent periods, including a cumulative loss over the last three years, coupled with its difficulty in forecasting future revenue trends as well as the cyclical nature of its business represent sufficient negative evidence to require a full valuation allowance against its U.S. federal and state net deferred tax assets as well as the above mentioned foreign jurisdictions. This valuation allowance will be evaluated periodically and can be reversed partially or in whole if business results and the economic environment have sufficiently improved to support realization of some or all of the Company's deferred tax assets.

The acquisition of Enterasys in October 2013 included a U.S. parent company as well as its wholly-owned foreign subsidiaries. The Company elected to treat this stock acquisition as an asset purchase by filing the required election forms under IRC Sec 338(h)(10). In addition, the Company completed asset purchases of the WLAN Business, the Campus Fabric Business and the Data Center Business in October 2016, July 2017 and October 2017, respectively. The Company has estimated the value of the intangible assets from these transactions and is amortizing the amounts over 15 years for tax purposes. During the three months ended September 30, 2018 and 2017, the Company deducted $0.5 million and $1.6 million of tax amortization expense respectively, for each period related to capitalized goodwill resulting from these acquisitions. As of September 30, 2018, the Company recorded a deferred tax liability of $5.9 million related to this goodwill amortization which is not considered a future source of taxable income in evaluating the need for a valuation allowance against its deferred tax assets.

The Company had $17.2 million of unrecognized tax benefits as of September 30, 2018. The future impact of the unrecognized tax benefit of $17.2 million, if recognized, would result in adjustments to deferred tax assets and corresponding adjustments to the valuation allowance. The Company does not anticipate any events to occur during the next twelve months that would reduce the unrealized tax benefit as currently stated in the Company’s balance sheet.

The Company’s policy is to accrue interest and penalties related to the underpayment of income taxes as a component of tax expense in the accompanying condensed consolidated statements of operations.

In general, the Company’s U.S. federal income tax returns are subject to examination by tax authorities for fiscal years 2001 forward due to net operating losses and the Company's state income tax returns are subject to examination for fiscal years 2000 forward due to net operating losses. The Company is in the process of settling examination by the state of North Carolina for fiscal years ended 2014, 2015 and 2016. The settlement will result in an immaterial payment to the state to close all three years.