Liabilities and Restructuring Charges - Summary of Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 6,026	$ 0	$ 31,038	$ 2,987
Employee Severance and Benefits
Restructuring Reserve [Roll Forward]
Liability as of October 31, 2016			5,679
Restructuring charges	6,000		31,038
Cash (payments)	(2,700)		(21,523)
As of July 31, 2017	$ 15,194		$ 15,194