Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Apr. 30, 2012	Apr. 30, 2012
Income Taxes [Line Items]
Valuation Allowance, Deferred Tax Asset, Change in Amount	$ 181
Income Taxes Percent Likelihood Of Being Realized Upon Settlement	50.00%	50.00%
Liability for uncertain tax positions	13	13
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	17	17
Tax Adjustments, Settlements, and Unusual Provisions		11
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	0	0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 25	$ 25

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Income Taxes Percent Likelihood Of Being Realized Upon Settlement

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- Definition

The estimated lower bound of the reasonably possible change in the total amount of the unrecognized tax benefit (that will significantly increase or decrease within twelve months of the balance sheet date) for a tax position taken.

+ References

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The estimated upper bound of the reasonably possible change in the total amount of the unrecognized tax benefit (that will significantly increase or decrease within twelve months of the balance sheet date) for a tax position taken.

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- Definition

Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings.

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- Definition

The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.

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-Glossary Unrecognized Tax Benefit

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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The amount of the change in the period in the valuation allowance for a specified deferred tax asset.

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