Significant Accounting Policies (Details)	6 Months Ended
	Apr. 30, 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 [Member]
Significant Accounting Policies [Line Items]
Measurement period for marketable debt securities (in years)	1 year
Derivative maturity (in months)	12 months
Maximum [Member] | Equipment, Furniture and Fixtures [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	5 years
Maximum [Member] | Software and Website Development [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	5 years
Minimum [Member]
Significant Accounting Policies [Line Items]
One-time employee termination benefits related to service period (in days)	60 days
Minimum [Member] | Equipment, Furniture and Fixtures [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	2 years
Minimum [Member] | Software and Website Development [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives capitalized and amortized straight-line, minimum (in years)	2 years