Summary of Business and Significant Accounting Policies - Accounts Receivable Allowance For Credit Loss Rollforward (Details) $ in Thousands	9 Months Ended
	Oct. 31, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 5,150
Provision for credit losses	17,070
Write-offs	(5,720)
Ending balance	$ 16,500