Summary of Business and Significant Accounting Policies - Accounts Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts receivable, gross	$ 331,547
Less: Allowance for credit losses	(20,500)	$ (5,150)
Less: Allowance for returns	(16,344)
Accounts receivable, net	$ 294,703