Taxes - Provision for Income Taxes and Effective Tax Rates (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Income Tax Disclosure [Abstract]
Income before income taxes	$ 147,055	$ 120,103
Provision (benefit) for income taxes	$ (6,459)	$ 123,794
Effective tax rate	(4.40%)	103.10%