Income Taxes	9 Months Ended
Jul. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We compute, on a quarterly basis, an estimated annual effective tax rate considering ordinary income and related income tax expense. For all periods presented, U.S. and certain foreign results are excluded from ordinary income due to ordinary losses for which no benefit can be recognized. Ordinary income refers to income (loss) before income tax expense excluding significant unusual or infrequently occurring items. The tax effect of a significant unusual or infrequently occurring item is recorded in the interim period in which the item occurs. Items included in income tax expense in the periods in which they occur include the tax effects of cumulative changes in tax laws or rates, foreign exchange gains and losses, adjustments to uncertain tax positions, and adjustments to our valuation allowance due to changes in judgment regarding the ability to realize deferred tax assets in future years. In the third quarter of 2017, in accordance with the intraperiod tax allocation rules, we recorded a net benefit of $35 million in Income tax expense related to domestic continuing operations, and an offsetting reduction in Other comprehensive income, which resulted from gains due to the remeasurement of certain pension and OPEB plans. The net benefit was offset by an increase in foreign taxes in Canada and Mexico. For more information, see Note 7, Postretirement Benefits. We have evaluated the need to maintain a valuation allowance for deferred tax assets based on our assessment of whether it is more likely than not that deferred tax benefits will be realized through the generation of future taxable income. Appropriate consideration is given to all available evidence, both positive and negative, in assessing the need for a valuation allowance. We continue to maintain a valuation allowance on the majority of our U.S. deferred tax assets as well as certain foreign deferred tax assets that we believe, on a more-likely-than-not basis, will not be realized based on current forecasted results. For all remaining deferred tax assets, while we believe that it is more likely than not that they will be realized, we believe that it is reasonably possible that additional deferred tax asset valuation allowances could be required in the next twelve months. We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such a position are measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. As of July 31, 2017, the amount of liability for uncertain tax positions was $49 million. The liability at July 31, 2017 has a recorded offsetting tax benefit associated with various issues that total $14 million. If the unrecognized tax benefits are recognized, all would impact our effective tax rate. However, to the extent we continue to maintain a full valuation allowance against certain deferred tax assets, the effect may be in the form of an increase in the deferred tax asset related to our net operating loss carryforward, which would be offset by a full valuation allowance. We recognize interest and penalties related to uncertain tax positions as part of Income tax expense. For the three and nine months ended July 31, 2017, total interest and penalties related to our uncertain tax positions resulted in an income tax expense of less than $1 million, and $1 million, respectively. We have open tax years back to 2001 with various significant taxing jurisdictions including the U.S., Canada, Mexico, and Brazil. In connection with the examination of tax returns, contingencies may arise that generally result from differing interpretations of applicable tax laws and regulations as they relate to the amount, timing, or inclusion of revenues or expenses in taxable income, or the sustainability of tax credits to reduce income taxes payable. We believe we have sufficient accruals for our contingent tax liabilities. Annual tax provisions include amounts considered sufficient to pay assessments that may result from examinations of prior year tax returns, although actual results may differ. While it is probable that the liability for unrecognized tax benefits may increase or decrease during the next twelve months, we do not expect any such change would have a material effect on our financial condition, results of operations, or cash flows.

Income Taxes

We compute, on a quarterly basis, an estimated annual effective tax rate considering ordinary income and related income tax expense. For all periods presented, U.S. and certain foreign results are excluded from ordinary income due to ordinary losses for which no benefit can be recognized. Ordinary income refers to income (loss) before income tax expense excluding significant unusual or infrequently occurring items. The tax effect of a significant unusual or infrequently occurring item is recorded in the interim period in which the item occurs. Items included in income tax expense in the periods in which they occur include the tax effects of cumulative changes in tax laws or rates, foreign exchange gains and losses, adjustments to uncertain tax positions, and adjustments to our valuation allowance due to changes in judgment regarding the ability to realize deferred tax assets in future years. In the third quarter of 2017, in accordance with the intraperiod tax allocation rules, we recorded a net benefit of $35 million in Income tax expense related to domestic continuing operations, and an offsetting reduction in Other comprehensive income, which resulted from gains due to the remeasurement of certain pension and OPEB plans. The net benefit was offset by an increase in foreign taxes in Canada and Mexico. For more information, see Note 7, Postretirement Benefits.

We have evaluated the need to maintain a valuation allowance for deferred tax assets based on our assessment of whether it is more likely than not that deferred tax benefits will be realized through the generation of future taxable income. Appropriate consideration is given to all available evidence, both positive and negative, in assessing the need for a valuation allowance. We continue to maintain a valuation allowance on the majority of our U.S. deferred tax assets as well as certain foreign deferred tax assets that we believe, on a more-likely-than-not basis, will not be realized based on current forecasted results. For all remaining deferred tax assets, while we believe that it is more likely than not that they will be realized, we believe that it is reasonably possible that additional deferred tax asset valuation allowances could be required in the next twelve months.

We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such a position are measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. As of July 31, 2017, the amount of liability for uncertain tax positions was $49 million. The liability at July 31, 2017 has a recorded offsetting tax benefit associated with various issues that total $14 million. If the unrecognized tax benefits are recognized, all would impact our effective tax rate. However, to the extent we continue to maintain a full valuation allowance against certain deferred tax assets, the effect may be in the form of an increase in the deferred tax asset related to our net operating loss carryforward, which would be offset by a full valuation allowance.

We recognize interest and penalties related to uncertain tax positions as part of Income tax expense. For the three and nine months ended July 31, 2017, total interest and penalties related to our uncertain tax positions resulted in an income tax expense of less than $1 million, and $1 million, respectively.

We have open tax years back to 2001 with various significant taxing jurisdictions including the U.S., Canada, Mexico, and Brazil. In connection with the examination of tax returns, contingencies may arise that generally result from differing interpretations of applicable tax laws and regulations as they relate to the amount, timing, or inclusion of revenues or expenses in taxable income, or the sustainability of tax credits to reduce income taxes payable. We believe we have sufficient accruals for our contingent tax liabilities. Annual tax provisions include amounts considered sufficient to pay assessments that may result from examinations of prior year tax returns, although actual results may differ. While it is probable that the liability for unrecognized tax benefits may increase or decrease during the next twelve months, we do not expect any such change would have a material effect on our financial condition, results of operations, or cash flows.