Income taxes	6 Months Ended
Feb. 28, 2018
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The effective tax rate for the three and six months ended February 28, 2018 was 27.4% and 25.4% respectively, compared to 19.0% and 18.2% for the three and six months ended February 28, 2017. As further described below, the increase in the effective tax rate for the three and six months ended February 28, 2018 was significantly impacted by recording a provisional net discrete tax expense of $184 million, as a result of the U.S. tax law changes described below, which were enacted on December 22, 2017, and higher net discrete tax benefits in the prior year periods. In addition, the Company's results for the three and six months ended February 28, 2018 also include a net reduction to the Company’s estimated annual tax rate for the current year as a result of the U.S. tax law changes. Income taxes paid for the six months ended February 28, 2018 were $301 million, compared to $537 million for the six months ended February 28, 2017. U.S. tax law changes The United States government enacted comprehensive tax legislation in December 2017. The accounting guidance on income taxes generally requires the effects of new tax legislation to be recognized in the period of enactment. The SEC issued Staff Accounting Bulletin 118 (“SAB 118”), which provides for a measurement period of up to one year from the enactment date for companies to complete their accounting for the U.S. tax law changes. In accordance with the SEC staff guidance, companies must reflect the income tax effects of those aspects of the U.S. tax law changes for which the accounting is complete. To the extent a company’s accounting for the income tax effect of certain provisions of the U.S. tax law changes is incomplete but the Company is able to determine a reasonable estimate, a provisional estimate must be recorded in the Company’s financial statements. If companies cannot determine a provisional estimate for the effects of an aspect of the U.S. tax law changes, they should continue applying the accounting guidance on income taxes on the basis of the provisions of the tax laws in effect immediately before the U.S. tax law changes were enacted. The U.S. tax law changes include broad and complex changes affecting the Company’s fiscal 2018 results. Among other things, the U.S. tax law changes reduce the federal corporate tax rate from 35% to 21% effective January 1, 2018 and require companies to immediately accrue for and pay over an eight year period a one-time transition tax on certain un-repatriated earnings of foreign subsidiaries. The U.S. tax law changes also alter the taxation of foreign earnings, repeal of the deduction for domestic production activities and establish a global intangible low tax income (GILTI) regime, as well as base erosion anti-avoidance tax (BEAT). In connection with the Company’s initial analysis of the impact of the U.S. tax law changes, which is provisional and subject to change, the Company recorded a net discrete tax expense of $184 million during the three and six months ended February 28, 2018. This provisional net discrete tax expense arises from the Company’s accrual for the transition tax of $794 million, partly offset by a benefit of $610 million from re-measuring the Company’s net U.S. deferred tax liabilities. The Company’s deferred tax assets and liabilities were re-measured at an estimated blended federal corporate tax rate of 25.7% for fiscal 2018 as a result of the reduction in the corporate tax rate and certain other of the U.S. tax law changes. Based on the effective dates of certain aspects of the U.S. tax law changes as well as estimated data required to be used in the corresponding measurement calculations, the Company’s analysis of the income tax effects of the U.S. tax law changes could not be finalized as of February 28, 2018. As of February 28, 2018, while the Company made reasonable estimates of the impact of the transition tax and the remeasurement of its deferred tax assets and liabilities, the final impact of the U.S. tax law changes may differ from these estimates, due to, among other things, changes in its interpretations and assumptions, additional guidance and actions the Company may take. The Company expects to finalize such provisional amounts within the time period prescribed by SAB 118. The U.S. tax law changes created new rules that allow the Company to make an accounting policy election to either treat taxes due on future Global Intangible Low Tax Income (“GILTI”) inclusions in taxable income as either a current period expense or reflect such inclusions related to temporary basis differences in the Company’s measurement of deferred taxes. The Company’s analysis of the new GILTI rules is not complete; therefore, the Company has not made a policy election regarding the tax accounting treatment of the GILTI tax. The U.S. tax law changes have the potential to change the Company’s assertions with respect to whether earnings of the Company’s foreign subsidiaries should remain indefinitely reinvested. The Company continues to evaluate these changes, therefore, the Company has not made any changes to its indefinite reinvestment assertions.

Income taxes

The effective tax rate for the three and six months ended February 28, 2018 was 27.4% and 25.4% respectively, compared to 19.0% and 18.2% for the three and six months ended February 28, 2017. As further described below, the increase in the effective tax rate for the three and six months ended February 28, 2018 was significantly impacted by recording a provisional net discrete tax expense of $184 million, as a result of the U.S. tax law changes described below, which were enacted on December 22, 2017, and higher net discrete tax benefits in the prior year periods. In addition, the Company's results for the three and six months ended February 28, 2018 also include a net reduction to the Company’s estimated annual tax rate for the current year as a result of the U.S. tax law changes.

Income taxes paid for the six months ended February 28, 2018 were $301 million, compared to $537 million for the six months ended February 28, 2017.

U.S. tax law changes

The United States government enacted comprehensive tax legislation in December 2017. The accounting guidance on income taxes generally requires the effects of new tax legislation to be recognized in the period of enactment. The SEC issued Staff Accounting Bulletin 118 (“SAB 118”), which provides for a measurement period of up to one year from the enactment date for companies to complete their accounting for the U.S. tax law changes. In accordance with the SEC staff guidance, companies must reflect the income tax effects of those aspects of the U.S. tax law changes for which the accounting is complete. To the extent a company’s accounting for the income tax effect of certain provisions of the U.S. tax law changes is incomplete but the Company is able to determine a reasonable estimate, a provisional estimate must be recorded in the Company’s financial statements. If companies cannot determine a provisional estimate for the effects of an aspect of the U.S. tax law changes, they should continue applying the accounting guidance on income taxes on the basis of the provisions of the tax laws in effect immediately before the U.S. tax law changes were enacted.

The U.S. tax law changes include broad and complex changes affecting the Company’s fiscal 2018 results. Among other things, the U.S. tax law changes reduce the federal corporate tax rate from 35% to 21% effective January 1, 2018 and require companies to immediately accrue for and pay over an eight year period a one-time transition tax on certain un-repatriated earnings of foreign subsidiaries. The U.S. tax law changes also alter the taxation of foreign earnings, repeal of the deduction for domestic production activities and establish a global intangible low tax income (GILTI) regime, as well as base erosion anti-avoidance tax (BEAT).

In connection with the Company’s initial analysis of the impact of the U.S. tax law changes, which is provisional and subject to change, the Company recorded a net discrete tax expense of $184 million during the three and six months ended February 28, 2018. This provisional net discrete tax expense arises from the Company’s accrual for the transition tax of $794 million, partly offset by a benefit of $610 million from re-measuring the Company’s net U.S. deferred tax liabilities. The Company’s deferred tax assets and liabilities were re-measured at an estimated blended federal corporate tax rate of 25.7% for fiscal 2018 as a result of the reduction in the corporate tax rate and certain other of the U.S. tax law changes.

Based on the effective dates of certain aspects of the U.S. tax law changes as well as estimated data required to be used in the corresponding measurement calculations, the Company’s analysis of the income tax effects of the U.S. tax law changes could not be finalized as of February 28, 2018.

As of February 28, 2018, while the Company made reasonable estimates of the impact of the transition tax and the remeasurement of its deferred tax assets and liabilities, the final impact of the U.S. tax law changes may differ from these estimates, due to, among other things, changes in its interpretations and assumptions, additional guidance and actions the Company may take. The Company expects to finalize such provisional amounts within the time period prescribed by SAB 118. The U.S. tax law changes created new rules that allow the Company to make an accounting policy election to either treat taxes due on future Global Intangible Low Tax Income (“GILTI”) inclusions in taxable income as either a current period expense or reflect such inclusions related to temporary basis differences in the Company’s measurement of deferred taxes. The Company’s analysis of the new GILTI rules is not complete; therefore, the Company has not made a policy election regarding the tax accounting treatment of the GILTI tax.

The U.S. tax law changes have the potential to change the Company’s assertions with respect to whether earnings of the Company’s foreign subsidiaries should remain indefinitely reinvested. The Company continues to evaluate these changes, therefore, the Company has not made any changes to its indefinite reinvestment assertions.