Income Taxes	6 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rate for the quarter and year to date periods ended March 31, 2018 was (32.6)% and (123.3)% compared to 17.7% and 24.9% for the quarter and year to date periods in the prior year. The effective tax rate for the current quarter is lower than the comparable period in fiscal 2017 due to period tax benefits of $11.2 million primarily related to a change in a tax accounting method approved by the Internal Revenue Service in the current period. The change in accounting method resulted in a reduction in U.S. tax for prior year currency exchange losses. The effective tax rate for the year to date period is lower than the comparable period in fiscal 2017 due to the lower corporate tax rate and period tax benefits of $75.6 million primarily related to recording the items attributable to the new tax legislation in the U.S. as described below and the change in tax accounting method. The comparable prior year period included period tax benefits of $3.5 million primarily related to the adoption of the ASU 2016-09 partially offset by the expense to revalue the France deferred tax assets due to the law change that reduced the future corporate income tax rate in France. On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code which will impact our fiscal year ended September 30, 2018 including, but not limited to (1) reducing the U.S. federal corporate tax rate, (2) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries that may electively be paid over eight years, and (3) accelerated first year expensing of certain capital expenditures. The Tax Act reduces the federal corporate tax rate from 35 percent to 21 percent effective January 1, 2018. Internal Revenue Code Section 15 provides that our fiscal year ended September 30, 2018 will have a blended corporate tax rate of 24.5 percent, which is based on a proration of the applicable tax rates before and after effective date of the Tax Act. The statutory tax rate of 21 percent will apply for fiscal 2019 and beyond. The Tax Act also puts in place new tax laws that will impact our taxable income beginning in fiscal 2019, which include, but are not limited to (1) creating a Base Erosion Anti-abuse Tax (BEAT), which is a new minimum tax, (2) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries, (3) a new provision designed to tax currently global intangible low-taxed income (GILTI), which allows for the possibility of utilizing foreign tax credits and a deduction equal to 50 percent to offset the income tax liability (subject to some limitations), (4) a provision that could limit the amount of deductible interest expense, (5) the repeal of the domestic production activity deduction, (6) limitations on the deductibility of certain executive compensation, and (7) limitations on the utilization of foreign tax credits to reduce the U.S. income tax liability. Shortly after the Tax Act was enacted, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118) which provides guidance on accounting for the Tax Act’s impact. SAB 118 provides a measurement period, which in no case should extend beyond one year from the Tax Act enactment date, during which a company acting in good faith may complete the accounting for the impacts of the Tax Act under ASC Topic 740. In accordance with SAB 118, the Company must reflect the income tax effects of the Tax Act in the reporting period in which the accounting under ASC Topic 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete, the Company can determine a reasonable estimate for those effects and record a provisional estimate in the financial statements in the first reporting period in which a reasonable estimate can be determined. If a Company cannot determine a provisional estimate to be included in the financial statements, the Company should continue to apply ASC 740 based on the provisions of the tax laws that were in effect immediately prior to the Tax Act being enacted. If a Company is unable to provide a reasonable estimate of the impacts of the Tax Act in a reporting period, a provisional amount must be recorded in the first reporting period in which a reasonable estimate can be determined. We have recorded a provisional discrete net tax benefit of $61.4 million related to the Tax Act in the year to date period ending March 31, 2018. No additional adjustments were recorded in the current quarter. This net benefit primarily consists of a net benefit of $93.8 million due to the remeasurement of our deferred tax accounts to reflect the corporate rate reduction impact to our net deferred tax balances and a net expense for the transition tax of $32.4 million. Reduction in U.S. Corporate Rate: The Tax Act reduces the U.S. federal statutory corporate tax rate to 24.5 percent in fiscal year ending September 30, 2018 and 21 percent for fiscal year ending September 30, 2019 and beyond. We have recorded a provisional adjustment to our net deferred tax balances, with a corresponding discrete net tax benefit of $93.8 million in the current year to date period. In our annual effective tax rate we have reflected the tax effect of the temporary differences that will originate subsequent to the Tax Act and are required to be remeasured at the 21 percent tax rate. While we are able to make a reasonable estimate of the impact of the reduction in corporate rate, we are continuing to analyze the temporary differences that existed on the date of enactment, and the temporary differences originating in the current fiscal year. Transition Tax: The transition tax is a fiscal 2018 tax on the previously untaxed accumulated and current earnings and profits (E&P) of certain of our foreign subsidiaries. In order to determine the amount of the Transition Tax, we must determine, in addition to other factors, the amount of post-1986 E&P of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. E&P is similar to retained earnings of the subsidiary, but requires other adjustments to conform to U.S. tax rules. We are able to make a reasonable estimate of the transition tax and recorded a provisional transition tax obligation of $32.4 million which we expect to elect to pay, net of certain tax credit carryforwards, over eight years beginning in fiscal 2019. This amount is presented in Other long-term liabilities. However, we are awaiting further interpretative guidance, continuing to assess available tax methods and elections, and continuing to gather additional information to more precisely compute the amount of the transition tax. Global intangible low-taxed income (GILTI): The Tax Act includes a provision designed to currently tax global intangible low-taxed income starting in fiscal 2019. Due to the complexity of the new GILTI tax rules, we are continuing to evaluate this provision of the Tax Act, the application of ASC 740, and are considering available accounting policy alternatives to adopt to either record the U.S. income tax effect of future GILTI inclusions in the period in which they arise or establish deferred taxes with respect to the expected future tax liabilities associated with future GILTI inclusions. Our accounting policies depend, in part, on analyzing our global income to determine whether we expect a tax liability resulting from the application of this provision, and, if so, whether and when to record related current and deferred income taxes. Whether we intend to recognize deferred tax liabilities related to the GILTI provisions is dependent, in part, on our assessment of the Company's future operating structure. In addition, we are awaiting further interpretive guidance in connection with the computation of the GILTI tax. For these reasons, we are not yet able to reasonably estimate the effect of this provision of the Tax Act. Therefore, we have not made any adjustments relating to potential GILTI tax in our financial statements and have not made a policy decision regarding our accounting for GILTI. As of September 30, 2017, our practice and intention was to reinvest the earnings in our non-U.S. subsidiaries outside of the U.S., and no U.S. deferred income taxes or foreign withholding taxes were recorded. The transition tax noted above will result in the previously untaxed foreign earnings being included in the federal and state fiscal 2018 taxable income. We are currently analyzing our global working capital requirements and the potential tax liabilities that would be incurred if the non-U.S. subsidiaries distribute cash to the U.S. parent, which include local country withholding tax and potential U.S. state taxation. Furthermore, the transition tax will close a majority of the outside basis differences in our foreign corporations and any remaining temporary difference will potentially have some interaction with the GILTI tax noted above. For these reasons, we are not yet able to reasonably estimate the effect of this provision of the Tax Act and have not recorded any withholding or state tax liabilities, any deferred taxes attributable to GILTI (as noted above) or any deferred taxes attributable to our investment in our foreign subsidiaries. We are also currently analyzing other provisions of the Tax Act that come into effect for tax years starting October 1, 2018 to determine if these items would impact the effective tax rate. These provisions include BEAT, eliminating U.S. federal income taxes on dividends from foreign subsidiaries, the treatment of amounts in accumulated other comprehensive income, the new provision that could limit the amount of deductible interest expense, and the limitations on the deductibility of certain executive compensation.

Income Taxes

The effective tax rate for the quarter and year to date periods ended March 31, 2018 was (32.6)% and (123.3)% compared to 17.7% and 24.9% for the quarter and year to date periods in the prior year. The effective tax rate for the current quarter is lower than the comparable period in fiscal 2017 due to period tax benefits of $11.2 million primarily related to a change in a tax accounting method approved by the Internal Revenue Service in the current period. The change in accounting method resulted in a reduction in U.S. tax for prior year currency exchange losses. The effective tax rate for the year to date period is lower than the comparable period in fiscal 2017 due to the lower corporate tax rate and period tax benefits of $75.6 million primarily related to recording the items attributable to the new tax legislation in the U.S. as described below and the change in tax accounting method. The comparable prior year period included period tax benefits of $3.5 million primarily related to the adoption of the ASU 2016-09 partially offset by the expense to revalue the France deferred tax assets due to the law change that reduced the future corporate income tax rate in France.

On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code which will impact our fiscal year ended September 30, 2018 including, but not limited to (1) reducing the U.S. federal corporate tax rate, (2) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries that may electively be paid over eight years, and (3) accelerated first year expensing of certain capital expenditures. The Tax Act reduces the federal corporate tax rate from 35 percent to 21 percent effective January 1, 2018. Internal Revenue Code Section 15 provides that our fiscal year ended September 30, 2018 will have a blended corporate tax rate of 24.5 percent, which is based on a proration of the applicable tax rates before and after effective date of the Tax Act. The statutory tax rate of 21 percent will apply for fiscal 2019 and beyond.

The Tax Act also puts in place new tax laws that will impact our taxable income beginning in fiscal 2019, which include, but are not limited to (1) creating a Base Erosion Anti-abuse Tax (BEAT), which is a new minimum tax, (2) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries, (3) a new provision designed to tax currently global intangible low-taxed income (GILTI), which allows for the possibility of utilizing foreign tax credits and a deduction equal to 50 percent to offset the income tax liability (subject to some limitations), (4) a provision that could limit the amount of deductible interest expense, (5) the repeal of the domestic production activity deduction, (6) limitations on the deductibility of certain executive compensation, and (7) limitations on the utilization of foreign tax credits to reduce the U.S. income tax liability.

Shortly after the Tax Act was enacted, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118) which provides guidance on accounting for the Tax Act’s impact. SAB 118 provides a measurement period, which in no case should extend beyond one year from the Tax Act enactment date, during which a company acting in good faith may complete the accounting for the impacts of the Tax Act under ASC Topic 740. In accordance with SAB 118, the Company must reflect the income tax effects of the Tax Act in the reporting period in which the accounting under ASC Topic 740 is complete.

To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete, the Company can determine a reasonable estimate for those effects and record a provisional estimate in the financial statements in the first reporting period in which a reasonable estimate can be determined. If a Company cannot determine a provisional estimate to be included in the financial statements, the Company should continue to apply ASC 740 based on the provisions of the tax laws that were in effect immediately prior to the Tax Act being enacted. If a Company is unable to provide a reasonable estimate of the impacts of the Tax Act in a reporting period, a provisional amount must be recorded in the first reporting period in which a reasonable estimate can be determined.

We have recorded a provisional discrete net tax benefit of $61.4 million related to the Tax Act in the year to date period ending March 31, 2018. No additional adjustments were recorded in the current quarter. This net benefit primarily consists of a net benefit of $93.8 million due to the remeasurement of our deferred tax accounts to reflect the corporate rate reduction impact to our net deferred tax balances and a net expense for the transition tax of $32.4 million.

Reduction in U.S. Corporate Rate: The Tax Act reduces the U.S. federal statutory corporate tax rate to 24.5 percent in fiscal year ending September 30, 2018 and 21 percent for fiscal year ending September 30, 2019 and beyond. We have recorded a provisional adjustment to our net deferred tax balances, with a corresponding discrete net tax benefit of $93.8 million in the current year to date period. In our annual effective tax rate we have reflected the tax effect of the temporary differences that will originate subsequent to the Tax Act and are required to be remeasured at the 21 percent tax rate. While we are able to make a reasonable estimate of the impact of the reduction in corporate rate, we are continuing to analyze the temporary differences that existed on the date of enactment, and the temporary differences originating in the current fiscal year.

Transition Tax: The transition tax is a fiscal 2018 tax on the previously untaxed accumulated and current earnings and profits (E&P) of certain of our foreign subsidiaries. In order to determine the amount of the Transition Tax, we must determine, in addition to other factors, the amount of post-1986 E&P of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. E&P is similar to retained earnings of the subsidiary, but requires other adjustments to conform to U.S. tax rules. We are able to make a reasonable estimate of the transition tax and recorded a provisional transition tax obligation of $32.4 million which we expect to elect to pay, net of certain tax credit carryforwards, over eight years beginning in fiscal 2019. This amount is presented in Other long-term liabilities. However, we are awaiting further interpretative guidance, continuing to assess available tax methods and elections, and continuing to gather additional information to more precisely compute the amount of the transition tax.

Global intangible low-taxed income (GILTI): The Tax Act includes a provision designed to currently tax global intangible low-taxed income starting in fiscal 2019. Due to the complexity of the new GILTI tax rules, we are continuing to evaluate this provision of the Tax Act, the application of ASC 740, and are considering available accounting policy alternatives to adopt to either record the U.S. income tax effect of future GILTI inclusions in the period in which they arise or establish deferred taxes with respect to the expected future tax liabilities associated with future GILTI inclusions. Our accounting policies depend, in part, on analyzing our global income to determine whether we expect a tax liability resulting from the application of this provision, and, if so, whether and when to record related current and deferred income taxes. Whether we intend to recognize deferred tax liabilities related to the GILTI provisions is dependent, in part, on our assessment of the Company's future operating structure. In addition, we are awaiting further interpretive guidance in connection with the computation of the GILTI tax. For these reasons, we are not yet able to reasonably estimate the effect of this provision of the Tax Act. Therefore, we have not made any adjustments relating to potential GILTI tax in our financial statements and have not made a policy decision regarding our accounting for GILTI.

As of September 30, 2017, our practice and intention was to reinvest the earnings in our non-U.S. subsidiaries outside of the U.S., and no U.S. deferred income taxes or foreign withholding taxes were recorded. The transition tax noted above will result in the previously untaxed foreign earnings being included in the federal and state fiscal 2018 taxable income. We are currently analyzing our global working capital requirements and the potential tax liabilities that would be incurred if the non-U.S. subsidiaries distribute cash to the U.S. parent, which include local country withholding tax and potential U.S. state taxation. Furthermore, the transition tax will close a majority of the outside basis differences in our foreign corporations and any remaining temporary difference will potentially have some interaction with the GILTI tax noted above. For these reasons, we are not yet able to reasonably estimate the effect of this provision of the Tax Act and have not recorded any withholding or state tax liabilities, any deferred taxes attributable to GILTI (as noted above) or any deferred taxes attributable to our investment in our foreign subsidiaries.

We are also currently analyzing other provisions of the Tax Act that come into effect for tax years starting October 1, 2018 to determine if these items would impact the effective tax rate. These provisions include BEAT, eliminating U.S. federal income taxes on dividends from foreign subsidiaries, the treatment of amounts in accumulated other comprehensive income, the new provision that could limit the amount of deductible interest expense, and the limitations on the deductibility of certain executive compensation.