Borrowings (Narrative) (Details) $ / shares in Units, shares in Millions	1 Months Ended	3 Months Ended				12 Months Ended
	Jan. 31, 2015 USD ($) shares $ / shares	Oct. 31, 2015 USD ($) shares $ / shares		Jan. 31, 2015 USD ($)	Jan. 24, 2009	Oct. 31, 2015 USD ($) $ / shares shares		Nov. 01, 2014 USD ($)	Oct. 26, 2013 USD ($)	Jan. 14, 2015 USD ($) $ / shares shares	Jan. 22, 2013 USD ($)	Jan. 20, 2010 USD ($)	Oct. 31, 2008 USD ($)
Convertible Debt [Abstract]
Proceeds from convertible notes						$ 565,656,000		$ 0	$ 0
Payments for Hedge, Financing Activities						86,135,000		0	0
Proceeds from issuance of warrants						$ 51,175,000		0	0
Convertible Senior Unsecured 2020 Notes [Member]
Convertible Debt [Abstract]
Debt instrument, face amount										$ 575,000,000
Proceeds from convertible notes	$ 565,700,000
DiscountRateForFairValueOfLiabilityComponent	4.57%
Debt Instrument, Convertible, Remaining Discount Amortization Period						4 years 2 months 1 day
Amortization of Debt Discount (Premium)						$ 12,900,000
Interest Expense, Debt, Excluding Amortization						6,300,000
Long-term debt, fair value		$ 568,000,000				$ 568,000,000
Debt Instrument, Maturity Date Range, End	Jan. 01, 2020					Jan. 01, 2020
Debt Instrument, Convertible, Conversion Ratio	62.7746	62.8879
Debt Instrument, Convertible, Number of Equity Instruments | shares	36.1	36.2
Debt Instrument, Convertible, Conversion Price | $ / shares		$ 15.90	[1],[2]			$ 15.90	[1],[2]			$ 15.93
Debt Instrument, Convertible, If-converted Value in Excess of Principal						$ 0
Repurchase price of notes in case of change in control, percentage of face value	100.00%
Option Indexed to Issuer's Equity, Indexed Shares | shares										36.1
Option Indexed to Issuer's Equity, Strike Price | $ / shares	$ 15.93	$ 15.90
Payments for Hedge, Financing Activities	$ 86,100,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares		36.2				36.2				36.1
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares		$ 20.61				$ 20.61				$ 20.65
WarrantsMaturityPeriod	60 days
Class of Warrant or Right, Date from which Warrants or Rights Exercisable	Apr. 01, 2020
Proceeds from issuance of warrants	$ 51,200,000
Unsecured Debt [Abstract]
Debt instrument, face amount										$ 575,000,000
Long-term debt, fair value		$ 568,000,000				$ 568,000,000
Repurchase price of notes in case of change in control, percentage of face value	100.00%
Secured Debt [Abstract]
Debt instrument, face amount										575,000,000
Long-term debt, fair value		568,000,000				$ 568,000,000
Interest Expense, Debt								0	$ 0
Senior Secured 2020 Notes
Convertible Debt [Abstract]
Debt instrument, face amount												$ 300,000,000
Long-term debt, fair value								312,500,000
Debt Instrument, Maturity Date Range, End						Jan. 01, 2015
Unsecured Debt [Abstract]
Debt instrument, face amount												300,000,000
Long-term debt, fair value								312,500,000
Secured Debt [Abstract]
Debt instrument, face amount												$ 300,000,000
Debt Instrument, Redemption Price, Percentage						103.438%
Irrevocable deposit										322,200,000
Repayment of principal amount										300,000,000
Call premium										10,300,000
Debt Instrument, Increase, Accrued Interest				$ 10,300,000
Unpaid interest deposited to escrow										$ 1,600,000
Call premium cost and original issue discount and debt issuance costs related to lenders that did not participate in refinancing						$ 20,400,000
Long-term debt, fair value								312,500,000
Senior Unsecured 2023 Notes
Convertible Debt [Abstract]
Debt instrument, face amount											$ 300,000,000
Long-term debt, fair value		293,900,000				$ 293,900,000		292,400,000
Debt Instrument, Maturity Date Range, End						Jan. 15, 2023
Repurchase price of notes in case of change in control, percentage of face value						101.00%
Unsecured Debt [Abstract]
Debt instrument, face amount											300,000,000
Long-term debt, fair value		293,900,000				$ 293,900,000		292,400,000
Redemption price, percentage of face value						100.00%
Redemption amount of notes, percentage of principal amount, when using the net cash proceed from capital stock sale						35.00%
Redemption price, percentage of principal amount, when using the net cash proceed from capital stock sale						104.625%
Repurchase price of notes in case of change in control, percentage of face value						101.00%
Secured Debt [Abstract]
Debt instrument, face amount											$ 300,000,000
Long-term debt, fair value		293,900,000				$ 293,900,000		292,400,000
Term Loan Facility
Secured Debt [Abstract]
Debt Instrument, Original Term of Loan					5 years
Senior secured credit facility, maximum borrowing capacity													$ 1,100,000,000
Senior secured credit facility, amount outstanding		0				0		0
Revolving Credit Facility
Secured Debt [Abstract]
Debt Instrument, Original Term of Loan					5 years
Senior secured credit facility, maximum borrowing capacity		125,000,000				125,000,000		125,000,000					125,000,000
Senior secured credit facility, amount outstanding		$ 0				$ 0		$ 0
Swing Line Loan Subfacility
Secured Debt [Abstract]
Senior secured credit facility, maximum borrowing capacity													25,000,000
Letter Of Credit Subfacility
Secured Debt [Abstract]
Senior secured credit facility, maximum borrowing capacity													$ 25,000,000
Trading Price Trigger One [Member] | Convertible Senior Unsecured 2020 Notes [Member]
Convertible Debt [Abstract]
Debt Instrument, Convertible, Threshold Trading Days	20
Debt Instrument, Convertible, Threshold Consecutive Trading Days	30 days
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger	130.00%
Trading Price Trigger Two [Member] | Convertible Senior Unsecured 2020 Notes [Member]
Convertible Debt [Abstract]
Debt Instrument, Convertible, Threshold Trading Days	5
Debt Instrument, Convertible, Threshold Consecutive Trading Days	10 days
Debt Instrument, Convertible, Threshold Percentage of Notes Price Trigger	98.00%

[1] In connection with the issuance of the 2020 Convertible Notes, the Company entered into convertible note hedge and warrant transactions as described in Note 8, “Borrowings.” The 2020 Convertible Notes have no impact on diluted earnings per share until the average quarterly price of the Company’s common stock exceeds the adjusted conversion price of $15.90 per share. If the common stock price exceeds this adjusted conversion price, prior to conversion, the Company will calculate the effect of the additional shares that may be issued using the treasury stock method. If the average price of the Company’s common stock exceeds $20.61 per share for a quarterly period, the Company’s weighted-average shares used in computing diluted net income per share will be impacted by the effect of the additional potential shares that may be issued related to the warrants using the treasury stock method. The convertible note hedge is not considered for purposes of the diluted earnings per share calculation, as its effect would be antidilutive.

[2] These amounts are excluded from the computation of diluted net income per share.