Accrued Liabilities and Other Short-Term Obligations - Narrative (Details) - USD ($) shares in Millions		3 Months Ended
	Nov. 15, 2018	Jan. 31, 2019	Jan. 31, 2018	Oct. 31, 2018	Aug. 30, 2018
Debt Instrument [Line Items]
Debt conversion liability		$ 0		$ 164,212,000
Payment for debt conversion liability		$ 111,268,000	$ 0
3.75% Convertible Senior Notes due October 15, 2018 (New)
Debt Instrument [Line Items]
Interest rate on convertible notes (as a percent)				3.75%	3.75%
Convertible notes payable | 3.75% Convertible Senior Notes due October 15, 2018 (New)
Debt Instrument [Line Items]
Maximum cash settlement					$ 400,000,000
Debt conversion liability					$ 164,200,000
Payment for debt conversion liability	$ 111,300,000
Shares issued for debt conversion liability (in shares)	1.6