Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jan. 31, 2014	Jan. 31, 2013
Significant Accounting Policies [Line Items]
Expected economic lives of finite-lived intangible assets, maximum (in years)	7 years
Expected number of years Spares usage cost is expensed (in years)	4 years
4.0% Convertible Senior Notes due March 15, 2015 [Member]
Significant Accounting Policies [Line Items]
Interest rate on convertible notes	4.00%
Maximum
Significant Accounting Policies [Line Items]
Measurement period for marketable debt securities (in years)	1 year
Derivative maturity (in months)	12 months
Maximum | Equipment, Furniture and Fixtures [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	5 years
Maximum | Software and Website Development [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	5 years
Minimum
Significant Accounting Policies [Line Items]
One-time employee termination benefits related to service period (in days)	60 days
Minimum | Equipment, Furniture and Fixtures [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	2 years
Minimum | Software and Website Development [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	2 years
Interest and Other Income, Net [Member]
Significant Accounting Policies [Line Items]
Net loss on foreign currency re-measurement and exchange rate changes	$ 5.9	$ 0.2
Increase (decrease) in fair value of embedded redemption feature	(1.1)	0.3
Gain (loss) on foreign currency forward contracts	$ 1.4	$ (0.2)