Taxes - Provision for Income Taxes and Effective Tax Rates (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Income Tax Disclosure [Abstract]
Income before income taxes	$ 112,791	$ 85,231	$ 283,172	$ 246,796
Provision (benefit) for income taxes	$ (3,960)	$ 20,513	$ 26,527	$ 52,667
Effective tax rate	(3.50%)	24.10%	9.40%	21.30%