Taxes - Provision for Income Taxes and Effective Tax Rates (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Income Tax Disclosure [Abstract]
Income before income taxes	$ 71,893	$ 112,791	$ 311,295	$ 283,172
Provision (benefit) for income taxes	$ (7,516)	$ (3,960)	$ 133,105	$ 26,527
Effective tax rate	(10.50%)	(3.50%)	42.80%	9.40%