Balance Sheet Components - Rollforward of Allowance For Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 20,500	$ 5,150
Provision for credit losses	1,028	3,771
Write-offs	(3,528)	(621)
Ending balance	$ 18,000	$ 8,300