Income Taxes - Provision for Income Taxes and Effective Tax Rates (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Income before income taxes	$ 215,995	$ 110,166	$ 393,099	$ 209,739
Provision (benefit) for income taxes	$ 21,193	$ 246	$ 36,269	$ (4,242)
Effective tax rate	9.80%	0.20%	9.20%	(2.00%)