Short-Term and Long-Term Debt - Outstanding Convertible Notes Payable Debt Components (Details) $ in Thousands	3 Months Ended
	Jan. 31, 2018 USD ($)
3.75% Convertible Senior Notes due October 15, 2018 (Original)
Debt Instrument [Line Items]
Interest rate on convertible notes (as a percent)	3.75%
3.75% Convertible Senior Notes due October 15, 2018 (New)
Debt Instrument [Line Items]
Interest rate on convertible notes (as a percent)	3.75%
4.0% Convertible Senior Notes due December 15, 2020
Debt Instrument [Line Items]
Interest rate on convertible notes (as a percent)	4.00%
Convertible notes payable | 3.75% Convertible Senior Notes due October 15, 2018 (Original)
Debt Instrument [Line Items]
Principal Balance	$ 61,270
Unamortized Debt Discount	0
Deferred Debt Issuance Costs	(145)
Net Carrying Value	61,125
Equity component, Net carrying value	0
Convertible notes payable | 3.75% Convertible Senior Notes due October 15, 2018 (New)
Debt Instrument [Line Items]
Principal Balance	288,730
Unamortized Debt Discount	(423)
Deferred Debt Issuance Costs	(680)
Net Carrying Value	287,627
Equity component, Net carrying value	0
Convertible notes payable | 4.0% Convertible Senior Notes due December 15, 2020
Debt Instrument [Line Items]
Principal Balance	205,906
Unamortized Debt Discount	(8,692)
Deferred Debt Issuance Costs	(881)
Net Carrying Value	196,333
Equity component, Net carrying value	$ 43,131
Accretion rate of principal amount	1.85%