Balance Sheet Components - Rollforward of Allowance For Credit Losses (Details) - USD ($) $ in Thousands	6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 20,500	$ 5,150
Provision for credit losses	8,029	13,723
Write-offs	(11,029)	(1,373)
Ending balance	$ 17,500	$ 17,500