Summary of Significant Accounting Policies - Changes in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands		12 Months Ended
		Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Allowance for Doubtful Accounts (Rollforward)
Balance at Beginning of Period		$ 9,046	$ 5,613	$ 5,165
Provisions		20,875	11,669	3,368
Write-offs	[1]	(1,357)	(8,236)	(2,920)
Balance at End of Period		$ 28,564	$ 9,046	$ 5,613

[1] Balances written off, net of recoveries.