Stockholders' Deficit - Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended			1 Months Ended				3 Months Ended
	Jan. 31, 2013	Oct. 31, 2012	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2009	Nov. 30, 2011	Oct. 31, 2011	Jan. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Jul. 31, 2013	Jul. 31, 2007	Apr. 30, 2014
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount		$ 75			$ 75
Common stock, shares issued			81,400,000	80,500,000
Preferred Stock, Shares Authorized			30,000,000
Proceeds from Issuance of Common Stock	14	192	0	14	192
Preferred Stock, Shares Issued			0
Preferred Stock, Par or Stated Value Per Share			$ 1
Debt Instrument, Unamortized Discount			82
Payments for Repurchase of Common Stock			0	0	75
Common stock, shares authorized			220,000,000	220,000,000
Common stock, par value			$ 0.10	$ 0.10
Preferred Stock [Member]
Class of Stock [Line Items]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right												0.001
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized		220,000			220,000								110,000
Preferred Stock, Par or Stated Value Per Share													$ 1
Common Stock [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues	763,534	10,666,666
Share Price	$ 18.75	$ 18.75			$ 18.75
Preference Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized		10,000,000			10,000,000
Preferred Stock, Par or Stated Value Per Share		$ 1.00			$ 1.00
Convertible Junior Preference Stock Series D [Member]
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share		$ 1.00			$ 1.00
Preferred Stock, Shares Outstanding			100,702	120,096
Preferred Stock, Liquidation Preference Per Share		$ 25			$ 25
Convertible Preferred Stock, Shares Issued upon Conversion		0.3125			0.3125
Preferred Stock, Dividend Rate, Percentage					120.00%
Three Point Zero Percent Senior Subordinated Convertible Notes [Member]
Class of Stock [Line Items]
Proceeds from Issuance of Warrants					87
Three Point Zero Percent Senior Subordinated Convertible Notes [Member] | Call Option [Member] | Convertible Subordinated Debt [Member]
Class of Stock [Line Items]
Payments for Derivative Instrument, Investing Activities						125
Four Point Five Zero Senior Subordinated Convertible Notes [Member] | Convertible Subordinated Debt [Member]
Class of Stock [Line Items]
Long-term Debt, Fair Value				177
Debt Instrument, Convertible, Carrying Amount of Equity Component				22
Debt Instrument, Unamortized Discount				1
Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member] | Convertible Subordinated Debt [Member]
Class of Stock [Line Items]
Long-term Debt, Fair Value														367
Debt Instrument, Convertible, Carrying Amount of Equity Component														44
Debt Instrument, Unamortized Discount														1
Maximum [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount								175
Accelerated Share Repurchases Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount								100
Treasury Stock, Shares, Acquired							2,542,609
Stock Repurchase Program, Remaining Authorized Repurchase Amount								20
October 2011 [Member]
Class of Stock [Line Items]
Accelerated Share Repurchases, Settlement (Payment) or Receipt									80		80
Accelerated Share Repurchases, Initial Price Paid Per Share								$ 33.60
October 2011 [Member] | Accelerated Share Repurchases Program [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired								2,380,952
November 2011 [Member]
Class of Stock [Line Items]
Accelerated Share Repurchases, Settlement (Payment) or Receipt									20		20
November 2011 [Member] | Accelerated Share Repurchases Program [Member]
Class of Stock [Line Items]
Treasury Stock, Additional Shares Acquired							161,657
Open Market Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount								75
Treasury Stock, Shares, Acquired									1,905,600
Payments for Repurchase of Common Stock										$ 5	$ 70