Income Taxes - Income Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Jul. 31, 2013	Jul. 31, 2012	Apr. 30, 2012	Jul. 31, 2013
Income Taxes [Line Items]
Tax Benefit		$ 173
Valuation Allowance, Deferred Tax Asset, Change in Amount			(181)
Income Taxes Percent Likelihood Of Being Realized Upon Settlement	50.00%			50.00%
Unrecognized Tax Benefits	90			90
Unrecognized Tax Benefits that Would Not Impact Effective Tax Rate	84			84
Tax Adjustments, Settlements, and Unusual Provisions	$ 2			$ 8
Liability for Uncertain Tax Benefits Time Range				12 months

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 10A, 10B, 10C

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 10

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration