Summary of Significant Accounting Policies - Components of Accounts Receivables (Details) - USD ($) $ in Thousands	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Accounts Receivable, Net
Accounts receivable	$ 563,592	$ 758,341
Unbilled accounts receivable	35,589	50,932
Total accounts receivable	599,181	809,273
Less allowance for credit losses	(30,680)	(28,564)	$ (9,046)	$ (5,613)
Total accounts receivable, net	$ 568,501	$ 780,709