Income Taxes - Income Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended		3 Months Ended			3 Months Ended
	Jul. 31, 2014	Apr. 30, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013	Oct. 31, 2013 State and Local Jurisdiction	Jan. 31, 2014 State and Local Jurisdiction	Jan. 31, 2013 State and Local Jurisdiction	Apr. 30, 2014 Senior Subordinated Notes [Member]
Income Taxes [Line Items]
Income Tax Expense (Benefit)	$ 14		$ 16	$ 25	$ 53				$ (13)
Deferred Tax Assets, Valuation Allowance		29
Income Taxes Percent Likelihood Of Being Realized Upon Settlement	50.00%			50.00%
Liability for uncertain tax positions	50			50
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0			(2)
Liability for Uncertain Tax Benefits term range				12 days
Liability for Uncertain Tax Positions							(8)	12
Tax Adjustments, Settlements, and Unusual Provisions						$ 4