Income Taxes	6 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The quarterly income tax provision is calculated using an estimated annual effective tax rate, based upon expected annual income, permanent items, statutory rates and planned tax strategies in the various jurisdictions in which we operate. However, losses in certain jurisdictions and discrete items are treated separately. Deferred tax assets and liabilities reflect the tax effects of temporary differences between the carrying value of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. We record a valuation allowance if, based on the weight of available evidence, it is more likely than not that some portion or all of a deferred tax asset will not be realized. Our expectations regarding realization of our deferred tax assets is based upon the weight of all available evidence, including such factors as our recent earnings history, expected future taxable income and available tax planning strategies. In prior periods, we established valuation allowances on substantially all net deferred tax assets, after considering all of the available objective evidence, both positive and negative, historical and prospective, with greater weight given to historical evidence, and determined it is not more likely than not that these assets will be realized. The Tax Cuts and Jobs Act (the “Act”) was enacted on December 22, 2017, and permanently reduces the U.S. federal corporate tax rate from 35% to 21%, eliminated corporate Alternative Minimum Tax, modified rules for expensing capital investment, and limits the deduction of interest expense for certain companies. The Act is a fundamental change to the taxation of multinational companies, including a shift from a system of worldwide taxation with some deferral elements to a territorial system, current taxation of certain foreign income, a minimum tax on low-tax foreign earnings, and new measures to curtail base erosion and promote U.S. production. As a result of the Act, the statutory rate applicable to our fiscal year ending September 30, 2018 will be 24.5%, based on a fiscal year blended rate calculation. Accounting Standard Codification (“ASC”) 740 requires filers to record the effect of tax law changes in the period enacted. However, the SEC issued Staff Accounting Bulletin No. 118 (“SAB 118”), that permits filers to record provisional amounts during a measurement period ending no later than one year from the date of enactment. In the first quarter of fiscal 2018, we re-measured the applicable deferred tax assets based on the rates at which they are expected to reverse. We adjusted our gross deferred tax assets and liabilities and recorded a corresponding offset to our full valuation allowance against our net deferred tax assets, which resulted in minimal net effect to our provision for income taxes and effective tax rate. We have not made any other provisional adjustments as a result of the Act. The Act includes a one-time mandatory repatriation transition tax on certain net accumulated earnings and profits of our foreign subsidiaries. We are still in the process of analyzing the earnings and profits and tax pools of our foreign subsidiaries to reasonably estimate the effects of the one-time transition tax and, therefore, have not recorded a provisional impact. The tax expense impact of the one-time transition tax to be determined may be partially or fully offset by a release of valuation allowance for the utilization of existing net operating losses and tax credits that may reduce the amount of related taxes payable. We expect the accounting for this aspect of the Act to be complete by the end of fiscal 2018. As of March 31, 2018, consistent with historical conclusions, our cash balances held in foreign locations are expected to be permanently reinvested outside the United States as the impact of the Act on our current position is not yet fully understood and is still under evaluation. We are assessing the applicability of the other provisions in the Act and expect to complete this analysis by the end of fiscal 2018. For the three and six months ended March 31, 2018, we recorded an income tax benefit of $2.8 million and $1.5 million, respectively. Over the last several months, we have undertaken an effort to resolve an uncertain tax position in specific tax jurisdictions. We have worked with tax experts in the local jurisdictions and in the U.S. to review the transactions and tax laws that resulted in this uncertain tax position, as well as the related interest and penalties. At the conclusion of this review, we determined that the Company is not liable for withholding taxes nor the associated interest and penalties in one of the jurisdictions. Therefore, during the second quarter of fiscal 2018 we reversed the accrued tax, interest and penalties relating to this jurisdiction, which total $3.1 million, which was partially offset by income tax expense relating to our consolidated pre-tax income. The difference in our effective tax rate from the U.S. statutory rate primarily reflects the impact of the resolution of the uncertain tax position discussed above, as well as a mix of domestic and international pre-tax income and valuation allowance. In 2017 and in fiscal 2018, we reversed a portion of the valuation allowance related to net operating loss carryforwards which we have determined will be utilized against net operating income in the current year. We classify all of our uncertain tax positions as income taxes payable long-term. At March 31, 2018 and September 30, 2017, the total amount of unrecognized tax benefits was approximately $1.2 million and $4.2 million, respectively. Income taxes payable long-term includes other items, primarily withholding taxes that are not due until the related intercompany service fees are paid. We classify interest and penalties related to unrecognized tax benefits as income tax expense. As of March 31, 2018 and September 30, 2017, we had an accrual for potential interest and penalties of approximately $0.6 million and $2.6 million, respectively, classified with income taxes payable long-term. Amtech and one or more of our subsidiaries file income tax returns in The Netherlands, Germany, France, China and other foreign jurisdictions, as well as in the U.S. and various states in the U.S. We have not signed any agreements with the Internal Revenue Service, any state or foreign jurisdiction to the extend the statute of limitations for any fiscal year. As such, the number of open years is the number of years dictated by statute in each of the respective taxing jurisdictions, which generally is from 3 to 5 years.

Income Taxes

The quarterly income tax provision is calculated using an estimated annual effective tax rate, based upon expected annual income, permanent items, statutory rates and planned tax strategies in the various jurisdictions in which we operate. However, losses in certain jurisdictions and discrete items are treated separately.

Deferred tax assets and liabilities reflect the tax effects of temporary differences between the carrying value of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. We record a valuation allowance if, based on the weight of available evidence, it is more likely than not that some portion or all of a deferred tax asset will not be realized. Our expectations regarding realization of our deferred tax assets is based upon the weight of all available evidence, including such factors as our recent earnings history, expected future taxable income and available tax planning strategies. In prior periods, we established valuation allowances on substantially all net deferred tax assets, after considering all of the available objective evidence, both positive and negative, historical and prospective, with greater weight given to historical evidence, and determined it is not more likely than not that these assets will be realized.

The Tax Cuts and Jobs Act (the “Act”) was enacted on December 22, 2017, and permanently reduces the U.S. federal corporate tax rate from 35% to 21%, eliminated corporate Alternative Minimum Tax, modified rules for expensing capital investment, and limits the deduction of interest expense for certain companies. The Act is a fundamental change to the taxation of multinational companies, including a shift from a system of worldwide taxation with some deferral elements to a territorial system, current taxation of certain foreign income, a minimum tax on low-tax foreign earnings, and new measures to curtail base erosion and promote U.S. production.

As a result of the Act, the statutory rate applicable to our fiscal year ending September 30, 2018 will be 24.5%, based on a fiscal year blended rate calculation. Accounting Standard Codification (“ASC”) 740 requires filers to record the effect of tax law changes in the period enacted. However, the SEC issued Staff Accounting Bulletin No. 118 (“SAB 118”), that permits filers to record provisional amounts during a measurement period ending no later than one year from the date of enactment. In the first quarter of fiscal 2018, we re-measured the applicable deferred tax assets based on the rates at which they are expected to reverse. We adjusted our gross deferred tax assets and liabilities and recorded a corresponding offset to our full valuation allowance against our net deferred tax assets, which resulted in minimal net effect to our provision for income taxes and effective tax rate. We have not made any other provisional adjustments as a result of the Act.

The Act includes a one-time mandatory repatriation transition tax on certain net accumulated earnings and profits of our foreign subsidiaries. We are still in the process of analyzing the earnings and profits and tax pools of our foreign subsidiaries to reasonably estimate the effects of the one-time transition tax and, therefore, have not recorded a provisional impact. The tax expense impact of the one-time transition tax to be determined may be partially or fully offset by a release of valuation allowance for the utilization of existing net operating losses and tax credits that may reduce the amount of related taxes payable. We expect the accounting for this aspect of the Act to be complete by the end of fiscal 2018. As of March 31, 2018, consistent with historical conclusions, our cash balances held in foreign locations are expected to be permanently reinvested outside the United States as the impact of the Act on our current position is not yet fully understood and is still under evaluation.

We are assessing the applicability of the other provisions in the Act and expect to complete this analysis by the end of fiscal 2018.

For the three and six months ended March 31, 2018, we recorded an income tax benefit of $2.8 million and $1.5 million, respectively. Over the last several months, we have undertaken an effort to resolve an uncertain tax position in specific tax jurisdictions. We have worked with tax experts in the local jurisdictions and in the U.S. to review the transactions and tax laws that resulted in this uncertain tax position, as well as the related interest and penalties. At the conclusion of this review, we determined that the Company is not liable for withholding taxes nor the associated interest and penalties in one of the jurisdictions. Therefore, during the second quarter of fiscal 2018 we reversed the accrued tax, interest and penalties relating to this jurisdiction, which total $3.1 million, which was partially offset by income tax expense relating to our consolidated pre-tax income.

The difference in our effective tax rate from the U.S. statutory rate primarily reflects the impact of the resolution of the uncertain tax position discussed above, as well as a mix of domestic and international pre-tax income and valuation allowance. In 2017 and in fiscal 2018, we reversed a portion of the valuation allowance related to net operating loss carryforwards which we have determined will be utilized against net operating income in the current year.

We classify all of our uncertain tax positions as income taxes payable long-term. At March 31, 2018 and September 30, 2017, the total amount of unrecognized tax benefits was approximately $1.2 million and $4.2 million, respectively. Income taxes payable long-term includes other items, primarily withholding taxes that are not due until the related intercompany service fees are paid.

We classify interest and penalties related to unrecognized tax benefits as income tax expense. As of March 31, 2018 and September 30, 2017, we had an accrual for potential interest and penalties of approximately $0.6 million and $2.6 million, respectively, classified with income taxes payable long-term.

Amtech and one or more of our subsidiaries file income tax returns in The Netherlands, Germany, France, China and other foreign jurisdictions, as well as in the U.S. and various states in the U.S. We have not signed any agreements with the Internal Revenue Service, any state or foreign jurisdiction to the extend the statute of limitations for any fiscal year. As such, the number of open years is the number of years dictated by statute in each of the respective taxing jurisdictions, which generally is from 3 to 5 years.